Sep 28 – Oct 4, 2026 · Edition W40
What Reddit's builders are making this week
2,642 new projects from 9 builder subreddits, sorted into 200 groups and 23 themes. Fastest riser: Desktop window and dock utilities ▲ +69%.
The heatmap
Each square is one theme in one week, compared with that theme's own 12-week average. Hover or tap a square for the numbers; click it to see that week's projects.
Themes with fewer than 600 projects in 12 weeks are faded and marked "low sample", because small counts swing hard. Themes under 50 projects are left off the map.
Rising
Share of projects, last 4 weeks vs the 8 before. Groups with 40+ projects in the last 4 weeks.
- Desktop window and dock utilities▲ +69% 95 in 4w
- Local music and radio players▲ +68% 53 in 4w
- AI 3D model generation▲ +64% 58 in 4w
- AI short video generators▲ +62% 93 in 4w
- Home, cabinet and construction design tools▲ +54% 47 in 4w
- Browser strategy and simulation games▲ +47% 49 in 4w
- Photo library organizers and sharing▲ +41% 104 in 4w
- Browser extensions and utilities▲ +38% 50 in 4w
Cooling
Same comparison, biggest drops. Same 40-project minimum.
- Video game backlog trackers▼ -31% 42 in 4w
- All-in-one fitness and health trackers▼ -31% 49 in 4w
- Startup idea validation tools▼ -26% 45 in 4w
- Personal journaling apps▼ -25% 51 in 4w
- Sports fan games and tools▼ -23% 61 in 4w
- Travel and trip planners▼ -22% 65 in 4w
- Car ownership and maintenance apps▼ -22% 44 in 4w
- AI coding agent tooling▼ -22% 67 in 4w
Most built this week
| Group | Projects | vs prior 4 wks |
|---|---|---|
| Gym workout trackers | 40 | -3% |
| AI short video generators | 37 | ▲ +69% |
| AI image generation and creative canvases | 34 | +11% |
| Photo library organizers and sharing | 32 | -1% |
| Desktop window and dock utilities | 30 | ▲ +52% |
| AI chat organizers and prompt libraries | 28 | ▲ +87% |
| Personal to-do and daily planners | 26 | ▼ -24% |
| Personal budgeting and expense trackers | 26 | -16% |
| Multi-agent coding workspaces | 25 | +9% |
| Screen recording and screenshot tools | 24 | ▲ +31% |
| Daily logic puzzle games | 24 | +21% |
| Photo and image editors | 23 | -11% |
By theme
Games and gaming tools
Casual, puzzle, word, trivia, strategy, multiplayer and indie games plus trackers and tools for gamers and collectors.
212 projects · 9.6% share
- Daily logic puzzle games24
- Online card, board & party games21
- Casual mobile arcade games19
- Video game backlog trackers18
- Casual browser games16
- Browser strategy and simulation games13
- Browser racing and driving games13
- Trading card collection trackers13
- Trivia and quiz games12
- Tabletop RPG and RPG games12
- Chess training and analysis tools11
- AI-assisted game creation10
- Daily word puzzle games10
- Multiplayer browser games & matchmaking8
- Indie video game showcases7
- Geography guessing and quiz games5
- Cosmic Breach — Adds a Minecraft dimension split into four layers, each ending in a boss fight, with mobs, a mount, and custom boss AI and animations.“I let Opus 5.5 run for 54 hours straight and it built a full Minecraft boss mod ($2,032 of API usage) Part 1 of 4”
- Tiltanic — Lets players steer a boat through gates by tilting their phone in a browser game with a daily shared sea.“I turned phone tilting into a tiny boat game.”
- Simulates a fishing game with harbour scenes, fish collection, and moral dilemma mechanics across starting zones.“Week 9 of making my fishing game with the help of AI”
Creative media generation and editing
AI and manual tools for creating and editing images, video, 3D, music, audio, subtitles, stories and photo libraries.
210 projects · 8.3% share
- AI short video generators37
- AI image generation and creative canvases34
- Photo library organizers and sharing32
- Photo and image editors23
- AI and desktop video editors18
- AI 3D model generation16
- Audio playback and sound tools15
- Music practice and creation tools12
- AI music and song generation10
- AI story generation and fiction writing8
- Video subtitle generation and translation5
- Astra Blue — Turns the previous day's AI news into a song with a full AI-generated music video.“I vibe coded an AI pop star that sings the daily AI news”
- Provides native Rust open source clone implementations of several Adobe creative applications, including a Photoshop-style image editor.“100% Open Source Clean Room Implementations of 7 of Adobe's Top Apps”
- Generates a motion graphics video from prompts using an AI model, voiceover, and music.“Opus 5.5 Cooking the motion designers lol”
Desktop and device utilities
Window managers, clipboard tools, file cleanup, dictation, screen capture, input remapping, wallpapers and device dashboards for power users.
143 projects · 5.0% share
- Desktop window and dock utilities30
- Screen recording and screenshot tools24
- Local voice dictation apps18
- Android launchers and phone utilities15
- Device monitors and ambient displays13
- Desktop file organizers and cleanup12
- Alternative computer input & remote control12
- Desktop pet companions9
- Clipboard history managers5
- Wallpaper apps and live wallpapers5
- Tack+ — Opens a panel from the MacBook notch showing music controls, messages, clipboard history, stashed files, widgets and a focus timer.“I created a Mac app that opens your MacBook notch: push the cursor against it and your music, messages and clipboard are right there”
- Split-Flap — Displays text on a railway-style split-flap board animation in the browser.“Split-Flap, a railway-style flap board for any screen in the browser”
- Sharp — Streams a Mac's desktop to another Mac over Ethernet as a second display, using compressed video with lossless tiles for sharpness.“Use Your iMac as a High-Resolution Display Over Ethernet [Sharp 1.0 Beta 1]”
Personal productivity and notes
To-do lists, note-taking, calendars, reminders, focus timers, meeting notes and visual thinking tools for organizing work and life.
137 projects · 4.7% share
- Personal to-do and daily planners26
- Project management tools20
- Personal note-taking apps18
- Visual canvases and diagram generators16
- Pomodoro focus timers15
- Personal calendar apps14
- Personal reminder and nudge apps13
- AI meeting transcription and notes6
- AI voice note apps5
- Markdown editors and viewers4
- Stupido — Turns spoken brain dumps into to-do tasks with natural-language scheduling.“The best brain dump to-do app ever! (imo ;p) Stupido 4.0 is live!”
- Renotify — Saves incoming notifications captured through the iOS Shortcuts automation so they can be browsed and searched later.“iPhone never had notification history. iOS 27 changed that, so I built an app (free, on-device)”
- Workel — Runs a public roadmap where users suggest and vote on features, with AI helping build approved requests and emailing requesters when they ship.“We built a roadmap where users suggest features and our AI just builds them!”
Health, fitness and wellness
Workout, nutrition, medication, mood, journaling, mental wellness, spiritual and astrology apps for personal wellbeing.
137 projects · 4.5% share
- Gym workout trackers40
- Personal health and medication trackers21
- AI calorie and nutrition trackers17
- Personal journaling apps14
- Mental wellness and calm apps13
- Mood trackers and personality quizzes10
- All-in-one fitness and health trackers9
- Drink logging and cocktail apps6
- AI astrology and divination readings5
- Scripture and prayer apps2
- Kinoku — Tracks lifts, runs and daily steps in one account-free history and moves the user along real-world journey maps as they train.“I'm building a fitness tracker (yes one of the most crowded app categories), so I built something I couldn't find and actually needed + some fun quirky stuff”
- Logs meals from plain-language descriptions and estimates their calories, and answers questions about food.“Desperate. 3 months building this and 0 users.”
- Repchek — Watches lifting form through the camera, counts reps, coaches out loud during sets, and records sessions with a rep-by-rep breakdown.“Last week I posted the app that tells me when my lifting form is wrong. This is what I fixed after your feedback”
AI assistants, chat and model tools
Tools for organizing AI chats, comparing and routing LLMs, AI research, companions, desktop assistants and AI media detection.
134 projects · 5.1% share
- AI chat organizers and prompt libraries28
- AI browser automation extensions17
- LLM gateways and model comparison15
- AI research and source-cited answers13
- Desktop AI assistants13
- AI companion character chat13
- AI image detection and photo analysis13
- AI tool directories and usage trackers12
- Multi-AI decision debate tools10
- Ornymo — Answers customer support questions on a website using an AI chat widget trained on the owner's FAQs, added with a script tag.“Built an AI support widget, people say cool but never actually try it what am I missing?”
- Misanthropic — Answers any message with insulting roasts via a chatbot, and routes self-harm or abuse messages to a plain crisis-hotline response instead.“Misanthropic - An AI that tells you your idea is bad, you're worse, and to go f*** yourself”
- DataDaive — Automates data processing, analysis and reporting using AI agents.“Clicks Without login”
AI coding agents and agent orchestration
Tools for running, monitoring, orchestrating, securing and giving memory to AI coding agents and multi-agent systems.
133 projects · 5.8% share
- Multi-agent coding workspaces25
- AI coding agent tooling22
- Claude Code session monitors18
- AI agent orchestration platforms14
- AI agent security guardrails12
- Terminal workspaces for AI agents11
- AI coding agents for Git repos10
- Persistent memory for AI agents10
- Codebase analysis for AI-written code9
- MCP server tooling2
- Jackhamr — Lets users spin up teams of AI agents for departmental work and pays only for compute and LLM usage.“We built a great AI agent platform, but our compute costs are too high for free trials. How do we grow?”
- TokenFish — Shows remaining Codex and Claude Code quota and reset times in a small animated desktop widget.“I built a desktop widget for Codex and Claude Code limits. It has little fish.”
- CrickCoder — Provides pay-per-use AI autocomplete and chat inside VS Code and JetBrains sidebars, billed at raw API cost plus a margin.“I got tired of $20 mo AI subscriptions, built my own pay-per-use plugin, and immediately got destroyed by free-tier abuse.”
File, document and everyday web utilities
Privacy-friendly browser tools for PDFs, image conversion, documents, forms, QR codes, file sharing, vaults, links and calculators.
132 projects · 4.8% share
- Browser-based PDF toolkits22
- Browser image compressors and converters20
- Document scanning and processing tools17
- Browser-based utility tool collections16
- File sharing and transfer tools14
- Online calculators and math tools9
- Pricing and cost calculators9
- Encrypted vaults and password managers8
- URL shorteners and link-in-bio pages8
- QR code generators and scanners5
- Online form builders and autofill4
- Urlicer — Shortens URLs with privacy-friendly, cookieless click tracking and team workspaces with custom domains.“I made 10 product videos, what do I do next?”
- Convertessa — Converts files between over 1,100 format combinations for images, video, audio, documents, archives, eBooks and fonts, entirely on the local machine.“[Launch] I got tired of sketchy sites that upload your files just to convert them - so I built Convertessa, a native Mac app that converts 1,100+ formats completely offline”
- PRIVACUT — Detects sensitive information in PDFs, lets users review flagged items, and permanently redacts them before sharing.“I built a PDF redaction SaaS. Now I’m trying to figure out who actually needs it.”
Marketing, SEO and sales
Tools for content generation, social scheduling, SEO and AI search visibility, ads, outbound sales, email, app store optimization and analytics.
128 projects · 5.0% share
- Website audit and monitoring tools13
- SEO audit tools13
- AI outbound sales prospecting12
- Web and SaaS analytics dashboards11
- Reddit marketing and lead finding10
- AI email writing and outreach tools10
- Email inbox and infrastructure tools8
- AI search visibility trackers8
- Local business lead finders8
- AI marketing content generators7
- LinkedIn outreach and content tools7
- AI social media schedulers6
- App store optimization tools6
- AI paid ads management tools5
- App Store screenshot generators4
- Lists alternative apps for apps that have stopped working, so users can find replacements.“I don't know how to drive visitors to my website”
- FeedSheriff — Automatically filters and cleans out spam and unwanted emails from a connected inbox using rules and AI-based context understanding.“I built a Sheriff that arrests the junk in your inbox (Sound On)”
- Rewrites email drafts to match the sender's role, the recipient, and a chosen tone, or follows a custom prompt.“Almost gave up on my side project. This morning someone paid for it.”
Home, food and lifestyle
Family organizers, home inventory, meal planning, recipes, home design, pets, plants, wardrobes, real estate, shopping and dining.
122 projects · 4.3% share
- Home, cabinet and construction design tools16
- Meal planners with grocery lists16
- Pet health and care trackers15
- Price trackers and comparison tools14
- Shared family and household organizers14
- Home inventory and maintenance trackers13
- Real estate & rental tools10
- Digital wardrobe and virtual try-on8
- Recipe managers and generators7
- Restaurant discovery and group picking5
- Plant identification and care apps4
- Helps a couple plan meals, store recipes, and build grocery lists together.“I built an app to help my GF and I cook more instead of eating out”
- Grocery Detective — Compares local grocery store prices and weekly deals across chains by zip code and emails saved-item digests.“I got tired of checking prices at 6 grocery stores every week so I built Grocery Detective to check them all at once”
- EasyDen — Gives a household one shared place to manage chores, shared expenses, shopping, and maintenance.“I built EasyDen, a roommate app. The hard part isn't features, it's getting the second roommate to care”
Personal finance and investing
Budgeting, expense and subscription tracking, bill splitting, pay tracking, trading journals, stock research and crypto tools.
114 projects · 4.0% share
- Personal budgeting and expense trackers26
- Subscription and recurring charge trackers18
- Retail trading tools and journals13
- AI stock research tools11
- Investment portfolio trackers11
- Shift, hours and pay trackers10
- Receipt scanning & expense tracking6
- SEC filing stock research tools6
- Personal finance planners and trackers5
- Crypto trading and portfolio tools5
- Crypto wallets and payment tools2
- Group expense splitting apps1
- Renders companies as buildings on a 3D island, with building height scaled to market cap.“I vibe coded a 3D island where every building is a company”
- FlyBudget — Tracks monthly budgets, recurring transactions, accounts, and spending with cash flow and custom reports.“I spent the last couple months building a free, private, open-source budgeting app”
- Preburn — Joins per-customer Stripe revenue with AI provider call costs to show margin per customer and can deny, reroute, or cap requests before expensive calls run.“I created my first open-source project today, and it feels amazing”
Developer tools and infrastructure
Deployment platforms, databases, monitoring, security scanners, app builders and low-level tinkering projects for developers.
113 projects · 4.5% share
- Security scanners for AI-built apps18
- AI prompt-to-app builders17
- UI design extraction & AI design tools15
- Self-hosted app deployment & dev infra14
- Network diagnostics and VPN tools14
- Uptime and API monitoring10
- GitHub profile and repo tools9
- Hobby languages and operating systems7
- Database clients and SQL tools7
- Domain name search tools2
- PhreshOS — Provides a web-based desktop environment where users build and run web apps that handle auth and communication, and agents can use those apps directly.“i spent 6+ months building an actual OS for web apps”
- Sqlaris Studio — Provides a desktop-style GUI for browsing, editing, querying and maintaining PostgreSQL and MySQL/MariaDB databases.“I built my own database GUI for PostgreSQL and MySQL”
- MyIPSpot — Shows a visitor's IP address with map, IPv6 and VPN leak tests, DNS lookup, and HTTP header details without cookies or tracking.“I got tired of every "what's my IP" site being an ad-stuffed tracker, so I built a tracker-free one”
Entertainment, music and news consumption
Apps for discovering and tracking music, movies, TV, podcasts, radio, livestreams and curated news digests.
105 projects · 3.7% share
- Local music and radio players20
- Online video downloaders and players18
- Music discovery and sharing apps12
- TV, movie and anime trackers12
- Movie & TV recommendation trackers11
- AI news aggregators and digests10
- Livestream viewing and streamer tools7
- Internet radio players6
- Podcast apps and AI tools5
- AI news aggregators and digests4
- Sonik Music — Streams music from artists and lets listeners support them with virtual gifts, purchases and merchandise.“I got frustrated with music streaming, so I spent 1+ year building my own platform. Sonik Music is now a working web + iOS product.”
- Iris Briefings — Monitors news and sources around a topic, filters for new information, and delivers personalized weekly briefings and podcasts.“I am stuck and will take any advice or reccomendations I can get”
- Reeler — Recommends three movies or series based on a few titles the user loves, each with a short story pitch.“I built an AI movie recommender that you can try in 30 seconds, no account. Would love brutal feedback”
Travel, maps and outdoors
Trip planners, place discovery maps, GPS tracking, interactive globes, sky trackers, weather and car ownership apps.
97 projects · 3.3% share
- Map-based place discovery apps20
- GPS trip and ride tracking18
- Interactive world maps and globes18
- Travel and trip planners13
- Car ownership and maintenance apps11
- Sky, space and flight trackers10
- Consumer weather apps7
- DriveTone — Plays simulated engine sounds with RPM, shifting and engine braking in an EV, driven by phone GPS and IMU data.“I got bored of my EV sounding like a fridge, so I built this.”
- LeaveFriday — Weekly searches nonstop weekend flights from California airports to 24 destinations and pairs each with hotels, scoring each trip.“Friday: leave the office. Saturday: feet in the sand. Sunday: home. I built a site that finds the best way there and back.”
- Tracks bike rides with GPS, showing speed, distance, and an odometer that reminds when the chain needs oiling, with all data kept on the phone.“I built an app with no server, no ads, no purchases and no account. Here's what that cost me.”
Social networks, messaging and dating
Alternative social networks, encrypted and anonymous chat, dating and couples apps, greeting gifts, polls and event planning.
95 projects · 3.5% share
- Event planning and scheduling tools18
- Alternative and anonymous social networks17
- Personalized digital greeting gifts15
- Anonymous and community chat apps15
- Private encrypted messaging apps14
- Dating and couples apps12
- Opinion polls and civic tech4
- NOTHING — Takes real payments in exchange for nothing and records the buyer on a leaderboard.“Nothing Web!”
- Penpal Apps — Lets users send physical-style letters to strangers around the world and wait for replies instead of instant messaging.“2 weeks ago I launched my penpal app. Now I have ~200 users, zero revenue, and people are asking for iOS.”
- Decidr — Lets people post two photos or short clips side by side and have others vote by swiping, with comments, emoji reactions, global or private posts, and timed posts.“I built a social app. Promoting on TikTok gets likes, but not converting to downloads. I'm considering more niche targeting. Who would you target first?”
Digital wellbeing and habits
App and site blockers, social feed reshapers, habit trackers and wake-up alarms that help people control screen time and build routines.
87 projects · 3.1% share
- Habit tracker apps22
- YouTube browser extensions17
- Phone app blockers14
- Social media feed tools13
- Distracting website blockers12
- Challenge-to-dismiss alarm apps9
- OpenTweet — Provides a tool for working with tweets, though the post does not describe its features.“My little side project is not that little anymore”
- Lets fans tip YouTube creators on video ideas they plan to make, with payments routed through Stripe Connect and a small commission taken per tip.“Today was supposed to be my first platform launch. Then Stripe said no.”
- AppBlockr — Blocks social media apps until the user completes a self-set task, verified by a photo checked with AI.“I just got my first paying subscriber 🎉”
Small business and freelance operations
CRMs, invoicing, client management, ecommerce, AI receptionists, WhatsApp automation, marketplaces and reselling tools for small businesses.
83 projects · 3.3% share
- SMB operations and SaaS infrastructure14
- Shopify and ecommerce merchant tools14
- Resale marketplace listing tools12
- AI phone receptionists & voice agents10
- Freelance client management tools9
- Freelancer invoice generators9
- WhatsApp business automation tools8
- Freelance and local gig marketplaces6
- Handmade crafts and physical goods1
- Lets users build wishlists and gift ideas for family and friends, with metadata scraped from product links.“1 Month After Launch: What 4 Traffic Spikes Taught Me About App Marketing as a Solo Dev”
- Lists software products in a directory and adds optimizations to help them get indexed by AI search engines.“Looking for Advice as a 19 year old founder”
- Operava — Tracks the services behind each product, including monthly cost, renewal dates and uptime, in one dashboard.“I built a dashboard to stop forgetting which services my products pay for. What am I missing?”
Browser extensions and web reading
Extensions for managing tabs and bookmarks, clipping and summarizing pages, rewriting text and tweaking the browsing experience.
74 projects · 3.0% share
- Browser extensions and utilities21
- Bookmark managers18
- Browser tab managers17
- AI text rewriting tools13
- Browser reading and clipping tools5
- Outpace — Runs a typing game that measures typing speed, adapts difficulty to the player's skill, and posts scores to a global leaderboard.“I asked Claude Opus 5.5 to build a typing game end to end, from one prompt”
- DOMiltion — Lets users visually demolish elements of a web page they dislike, shown as a playful destruction effect.“DOMiltion - demolish sites which you don't like”
- intab — Adds an inline AI writer inside text fields in the browser for rewriting, summarizing, translating, and fixing grammar.“got tired of copy/pasting into chatgpt, so i made this inline AI tool”
Careers and job search
Job search assistants, resume tailoring, interview and conversation practice, coding interview prep and builder networking.
65 projects · 2.5% share
- AI job search assistants20
- AI conversation practice coaches14
- AI resume tailoring tools12
- AI mock interview practice8
- Founder and builder matchmaking7
- Coding interview practice tools4
- Records spoken practice on random topics and tracks filler words and sentence length over time.“Made my first sale ever”
- Techleads.fyi — Looks up which technologies a company uses in its tech stack.“I gave Claude Opus 5.5 one prompt and got a 32-second launch video with a synced soundtrack. Here's the prompt.”
- Vocalis — Gives timed 60-second speaking prompts and analyzes recorded answers with feedback on strengths, weaknesses and mistakes.“I'm building an AI SaaS around a problem that sounds incredibly simple: helping people actually practice communication.”
Education and learning
AI tutors, flashcards, language learning, video summarizers and reading tools for students and self-learners.
63 projects · 2.4% share
- AI study and tutoring apps22
- Ebook readers and book trackers13
- Language learning apps12
- AI flashcard study tools9
- YouTube AI summarizers & note-takers7
- bookplate — Manages a personal book library on a self-hosted server.“Self-hosted library app”
- Turns a question, topic, or learning material into a structured, visual learning format instead of a long text answer.“I built a product I believe is genuinely useful, but I have no idea how to get the first users”
- Solves quiz questions from cropped screenshots and offers AI sidebar chat, flashcard generation, and mind mapping for students.“My semi vibe coded project making £100+ every month”
Indie maker launch and validation
Platforms for validating ideas, launching and promoting side projects, building websites and exchanging feedback and testing.
62 projects · 2.4% share
- Website builders and portfolios21
- Startup idea validation tools13
- Indie project showcase and launch platforms12
- Indie app testing exchanges11
- Startup promotion and creator deals4
- Product feedback and testimonial tools1
- Lets users track or manage a personal task through a mobile app, according to the post's description of a consumer B2C app.“I'm going to quit my FT job to grow my mobile app generating $80 a month - pls change my mind”
- Does not state what the product does; post only reports user signups.“My side project quietly passed 1,000 users and I did not tell a single person in my real life”
- Presents a designer's portfolio website with hand-drawn illustrations, draggable desk items, scroll-driven animations, and an in-site character with section-specific dialogue.“I spent 5 weeks building my portfolio with lots of hand-drawn illustrations and whimsical interactions”
Sports fan apps
Sports management sims, trivia, prediction pools and live score tools for fans of football and other sports.
41 projects · 1.4% share
- worthwatching.football — Scores upcoming Champions League matches on how entertaining they are likely to be, using AI-researched team styles and rules about how playing styles clash.“I built a website that rates Champions League games on how fun they'll be”
- GeoFußball — Quizzes players on football questions and scores how close their map guess is to the related location.“I built a daily football geography game. 2 days after launch, players are already sharing it organically”
- rondomap — Provides a searchable library of football training drills with animated diagrams and a session planner that builds printable practice plans.“Just launched rondomap.com, a free drill library for football coaches”
Miscellaneous
A catch-all of loosely related or undescribed side projects that don't fit a clear category.
0 projects · 0.0% share
Didn't fit any group
155 projects this week were too far from every group. New kinds of projects show up here first.
- TableSwish — Lets players shoot a small ball into a hoop on a folding table as a skill-based tabletop basketball game.“We’ve spent the last 14 months building a tabletop basketball game. Would you actually play this?”
- Paternal — Guides expectant fathers through pregnancy with advice on following the pregnancy, supporting their partner, and preparing for fatherhood.“My app made 22K in its first month + 5 lessons”
- Prep66 — Offers practice questions, revision guides and mock exams for Part 66 aircraft maintenance licence exams.“My first SaaS took 9 months and 4k in ad spent and never made a penny. Here's what my second made in 4 weeks, and everything I learned.”
- Krate — Packages desktop apps as single portable .krate files that run on Mac, Windows and Linux using a shared installed runtime.“I built a format where the same app file runs on Mac, Windows and Linux”
- Why Planes Fly — Explains how airplane wings generate lift, addressing the controversy over the common textbook explanations.“Why do Airplanes Fly?”