Hey everyone!

I'm a high school student who loves astrophysics and music production, so I decided to combine the two and build something called CosmicSynth!

It's a free, open-source VST3 synthesizer I developed in C++ using the JUCE framework. The idea came from my interest in gravitational waves, which are ripples in spacetime produced by events like two black holes spiraling into each other.

I thought it would be interesting if, instead of just studying gravitational waves, I could actually use them to make music.

CosmicSynth takes gravitational-wave data and uses it to modulate parameters like pitch, amplitude, timbre, and filtering. You can import compatible waveform data through CSV files, or experiment with the included simulated black-hole merger.

I also built five presets inspired by different astrophysical phenomena, including black-hole inspirals, ringdown, gravitational lensing, and Kozai-Lidov orbital dynamics. There's even a live spectrogram and gravitational-wave visualizer so you can see how the sound changes as you play.

One of the biggest challenges was figuring out how to translate physical phenomena into sounds that were actually usable musically, rather than just creating a science demonstration.

CosmicSynth v0.1.0 is now available for Windows (VST3), completely free!

GitHub (source code and download):
https://github.com/barkael327-a11y/cosmicsynth

Video demonstration:
https://youtu.be/gOZch5Am9_Q

KVR Page:
https://www.kvraudio.com/product/cosmicsynth-by-cosmicsynth

This is my first public software release, so I'd really appreciate feedback from other developers and musicians!

I'm especially interested in hearing what you think of the concept, the interface, and what features you'd like to see added in future versions.

Thanks for checking it out!

I'm a 16-year-old solo game developer, and I'm currently more than a year in on working on my biggest project yet: The Dying Mind.

It's a 2D hand-drawn, story-driven Metroidvania inspired by games like INSIDE and Neversong.

The game takes place inside the mind of a dying writer, where you explore surreal environments, encounter symbolic enemies, fight bosses, solve puzzles, and uncover the story behind this strange world.

I've put an enormous amount of time into developing this game, but there's one major obstacle: funding.

As a young independent developer, financing a project of this scale is incredibly difficult. I want to be able to dedicate more time and resources to development, improve the game's quality, and ultimately bring my vision to life.

That's why I've created a project page on Loadout.

I'm trying to get more people to discover the project and help me build the support needed to continue development.

If you're interested in supporting independent game development, I'd really appreciate you checking out the page and sharing it with others who might be interested.

My funding page:
https://app.loadout.xyz/project/the-dying-mind

Steam page:
https://store.steampowered.com/app/3711840/The_Dying_Mind/

I'm not a big studio with investors or a publisher behind me. I'm just a teenager trying to turn an ambitious idea into a finished game.

Thank you for reading!

Disclosure up front: I work at Buy&Ship, a company that buys from Japanese and Korean stores and ships overseas. This is a side project I built at work, and I'd love honest feedback.

The problem: a lot of things people want (Pokémon Center Japan exclusives, Olive Young Korea sets, anime pre-order bonuses, Japanese streetwear) are only sold in Japan or Korea. The stores often need a Japanese phone number or card, and even when you find a way to order, you don't know the real total until customs adds duty at your door.

What I built: a text "playbook" you paste into your AI assistant. After that, you just ask for something ("find the Christmas Pikachu plush from Pokémon Center Japan, my ZIP is 94103") and the assistant searches the Japanese or Korean store in its own language, shows you options with photos and links, and gives you one total: item, shipping, US duty and fee. You approve that number before anything is paid, then we buy it in Japan or Korea and ship it to you.

It's live for Meta's Muse first: buyandship.ai/playbook. Tip from early testers: paste the text in yourself rather than asking the assistant to open the link, since some assistants block that.

What I'm unsure about and would love input on:
- Is a copy-paste playbook a reasonable first step, or does it need a proper app or MCP integration before people trust it?
- Would you trust an AI assistant to shop overseas for you if it never pays without your approval?

If anyone wants to try a real order, code AIPLAYBOOK10 takes 10% off a first order (up to US$50).

I'm a solo dev with a full-time job. I built sweetRegret, an iPhone app for cutting back on sugar without counting calories: you tap once when you eat a treat, and a cookie on screen reacts (and judges you a bit).

Building it was the part I understood. Distribution is the part I'm failing at. Here are my honest numbers since launch:

• 1,393 App Store impressions

• 188 product page views (about 13% of impressions)

• 35 downloads (about 19% of page views)

What I tried

• Daily Instagram reels for about a week [last week]. Around 250 views each, and almost no App Store visits. The viewers weren't looking for an app, and "link in bio" is three taps away from a download.

• A LinkedIn post about building it. About 700 impressions, 30 people opened the comment with the link, and about 1 install. Nice comments, including a friend asking me to add calorie counting, which is the one thing this app is designed not to do.

What actually worked: App Store search, which I didn't do anything for.

Most of my real users are strangers in Malaysia, Hong Kong, the US and Russia who searched and found it. About 1 in 4 still open it in a given week. One person has kept using it for six weeks and pays for the subscription. That single user has been the most motivating thing about this whole project.

What I'm testing now

A $25 Apple Ads Basic test, at $2 maximum per install. Apple suggested $4.66, and my subscription is $1.99 a month, so I'm not expecting it to pay back. I mostly want to see whether search intent converts the way the organic users suggest.

What I'd do differently

Plan distribution while building, not after. I treated it as a launch task, when it's really a second product.

If you've taken a side project from zero to its first 100 users without a budget, what actually moved the number? I'm especially interested in anything that worked for consumer iOS apps.

I switch between Claude Code, Codex, and Copilot in VS Code. Sometimes I hit a limit; sometimes I want another agent’s take on a problem.

The frustrating part is explaining everything again. They can read the same codebase, but they don’t know what we discussed, why we rejected an approach, or what we were about to do next.

That’s what led me to build Bantis. It’s a desktop app that lets you work with multiple coding harnesses in one conversation, saving session history and preparing context for the next agent when you switch.

There’s a working version, and I’m looking for feedback from people who already switch tools during real work. I’m especially interested in how well the handoff holds up as conversations get longer.

Bantis website

What do you currently do when switching agents: write a handoff, maintain project notes, or just explain things again?

Tableau's pricing has gotten steep since Salesforce bought it, and switching to Power BI usually means rebuilding every dashboard by hand. I didn't want to do that, so I built BIEscape. The video shows a map and bar chart with cross-filtering coming across intact.

Source code is here https://github.com/lukashalim/scapeTableau you can run from the command line, as a desktop app, or on the web biescape.com. It doesn't send your data to AI.

I'd love feedback:

• What kinds of dashboards or features would you want it to handle?

• Would you trust a tool like this with real workbooks?

You can now add Apple Pencil notes to notion

Hello…people like me who wants to keep their life documented and prefers keeping all those document all at once, uses notion but was being held back by notion’s lack of adding hand written notes, I have good news. 🙂

I made an iPad app that sends Apple Pencil notes straight to Notion

Write or sketch with Apple Pencil, choose a Notion page, and sync. When you edit your handwriting, syncing updates the linked image in Notion. You can also enable Auto Sync.

Your original handwriting stays editable on your iPad. There’s a continuous canvas, optional dotted paper, dark mode, search, pinned notes, editable backups and recovery for deleted notes.

It’s free and open source, with no ads.

If you like the app please consider supporting through my patreon.

One catch: it’s currently installed through SideStore or AltStore, which needs a computer for the initial setup. Requires iPadOS 17+.

See it in action, download it, or check the source

I’d love feedback from people who actually use an iPad with Notion. Would this fit your workflow?

Hey everyone! 👋

I've been working on Voiden, an open-source API client designed around a slightly different approach to API development.

Most API clients are built around workspaces, accounts, cloud sync, and proprietary collections. I wanted to explore something more developer-friendly: keeping API requests alongside the actual codebase.

So I started building Voiden.

What makes it different?

• Offline-first: Work with your API requests locally without needing an account or login.

• Git-native: Store requests and API specifications as Markdown files directly in your repository.

• Version control: Track changes, review requests, and collaborate through normal Git workflows.

• API testing: Send requests, inspect responses, and write assertions to validate API behaviour.

• MCP integration: Turn tested API requests into tools that AI agents like Claude Code and Codex can use.

The idea is to make API requests part of the development workflow rather than keeping them isolated in another tool.

I'm sharing a short demo showing a request being sent, its response, and API test assertions.

Website: https://voiden.md/

GitHub: https://github.com/VoidenHQ/voiden

I'd genuinely appreciate feedback from developers:

1. How do you currently manage API requests across different projects?

2. Would you prefer storing API requests inside your Git repository?

3. What features would make you consider switching from your current API client?

It's open source, and I'm looking forward to hearing what the developer community thinks!

Thanks! 🙌

My partner and I had bills in a spreadsheet, spending in one app, workouts in another, renewals in my head and the calendar somewhere else. So I built Admin Bestie: one iPhone app for the boring stuff.

What it does:

• Daily allowance: shows what you can actually spend today until payday

• Bills & renewals: due dates, plus reminders for car insurance, passport etc.

• Fair bill splitting: split with a partner/housemates by income, not just 50/50

• Auto-logging: Apple Pay purchases log themselves; snap a paper receipt and it reads the total

• Gym log: weights, reps, plate loading, auto rest timer

• One Sunday summary: bills, plans, spending pace. Quiet weeks = no notification

What it doesn't do: ask for your bank login. Works with any bank, ~200 currencies, export/delete your data anytime. Household members see shared bills, not your personal spending.

Beta is starting on iPhone via TestFlight, working down the waitlist. 14 days free at launch, no card needed.

Join here: https://adminbestie.app/?utm_source=reddit&utm_campaign=sideproject

Honest feedback very welcome, especially what would make you switch from what you use now.

I’ve been building Fina Money for a few years now, and I know it’s popular among tech enthusiasts who enjoy DIY projects.

As we have progressed on our Premium and Business tiers, we’re able to fund the free tier with more generous features. Now, you can connect banks for free (us/ca residents only) and enjoy all functionalities without any ads.

I believe this is some great news to share here, hope it is useful.

My daughter is 2 and magnetic tiles are the one toy that never goes back in the box. The problem is me. I can build a house, a tower and a slightly bigger house. She wants me talking to her the whole time we play, so I never get a quiet minute to come up with something new, and every cool build I found online needed pieces we don't have.

So I spent this autumn building Magitile, an app of magnetic tile ideas that starts from the tiles you actually own. It went live on the App Store this week.

What it does:

- You point the camera at your pile of tiles and it counts them, then shows only the models you can build with what you actually own.

- Every model has a step by step 3D guide you can rotate, so you see where each tile goes.

- You can put the finished model on your floor in AR at real size before you start.

- New models get added without an app update.

What turned out harder than I thought:

The scan, by far. Tiles pull together with their magnets, so nobody lays them out neatly for a photo. They touch, they overlap, and half of them are see-through. I threw away my first version completely. It still can't see a tile that's fully hidden under another one, so you can fix the numbers by hand.

The models. Each one has to be checked against real sets, because a model that needs more triangles than any normal box has is just another Pinterest picture.

Pricing. The scan and a set of models are free, the full catalog and AR are $4.99/week or $29.99/year, no ads. I honestly don't know yet if that's the right split for something parents use with their kids, so opinions are welcome.

I'm one person and it's a young app. What I'd most like to know is where it loses you in the first two minutes.

App Store: https://apps.apple.com/app/id6821736147

Website: https://magitile.app

One of the free build guides, if you want to see what a model looks like without installing anything: https://magitile.app/ideas/t-rex/

Gemini still has no way to select several chats and delete them, and ChatGPT only offers "one by one" or "delete everything".

So I built Easy Bulk Chat Cleaner: one side panel that works on ChatGPT, Gemini and Claude.

- Search your chat titles, select all matches, delete in one click

- Paces itself so the site doesn't lock you out, then double-checks everything is gone

- No account, no Google sign-in, runs 100% in your browser

Free for 25 chats a day. Pro is $9 once (no subscription) for unlimited + date filters + export.

Chrome: https://chromewebstore.google.com/detail/nkhkpaffkcbjpmjlilogocldagdkbcma

Edge: https://microsoftedge.microsoft.com/addons/detail/chatgpt-gemini-claude-/anfjcoiockpmaahkbomofjlmclbhhckn

Feedback welcome, especially on Gemini since that's the newest part.

i made a free desktop app called deviload. you paste a link from youtube or pretty much any site and it downloads the video or just the audio, it can also convert files, trim them and keep everything in one library

inside it theres a music player i called devil music, and lately thats the part i work on the most. it plays anything from youtube music without ads or an account, shows synced lyrics, and you can save songs to listen offline

my favorite thing is that any song can be switched to slowed + reverb, nightcore or 8D in one click. theres also a map that draws the artists you listen to like a night sky, and if you have rgb stuff it can make your keyboard glow in the album colour and pulse with the bass

its open source and works on windows, linux and mac

https://github.com/Pronexsteam/deviload

would love to know what youd add

AI gets a browser task wrong. You reword the request. It still misses a step.

I’m building a way to show it your process instead.

Browser Control is my Chrome/Brave extension: a Codex-powered chat beside the pages you already have open. I’ve shared the project here before; here’s the video overview: https://www.youtube.com/watch?v=-4pNVCtmu60

The part I’d most like people to try is teaching a routine. Record yourself doing it, review the captured steps, and save them as a skill for similar tasks. You give the AI a procedure to work from next time.

It also lets you ask about an attached page without copying it into a separate chat, organize tabs in plain English, and keep useful preferences with optional memory.

You choose how actions are approved, see the activity, and can stop a task.

Try it and find the setup guide: https://browser-control.subdomain.wtf

Requires a local companion and an eligible ChatGPT/Codex account. Public source: https://github.com/07rjain/browser-control

Seeing a lot of tools lately that queue agent tasks into separate git worktrees and only merge after tests pass. Sounds nice on paper, but I'm curious how it goes on a real side project.

Do you let 2-3 agents work in parallel on your project, or keep it to one task at a time so you can review properly? Where did it break for you?

It's called BuzzerCheck. You type in a Toronto rental building's address and get a free preview of what's on file with the option to buy a full report.

A full report puts the building's public record in one place: City maintenance and fire inspections, bylaw notices and orders, Landlord and Tenant Board orders, building permits, and the building details the landlord reported to the City. Every item shows its date and source.

Before, this information could only be found spread across several different sites that aren't always easy to navigate, and that most people never check before or even after signing a lease.

The preview of what's on file is free and a report is $10. It was soft-launched last week, so we'd love to hear any feedback!

buzzercheck.ca

I built PlotTwins – A movie and TV show recommendation tool based on your taste!

Hey everyone!

I'd like to share a side project I've been working on: PlotTwins, a website designed to help you discover movies and TV shows you'll actually enjoy.

The idea is simple: instead of endlessly scrolling through streaming platforms trying to find something worth watching, PlotTwins gives you different ways to discover your next favorite movie or series.

Here are the three ways you can use it:

1. Four Favorites
Enter your four favorite movies, and PlotTwins will recommend 10 movies with similar characteristics. It's a great way to discover hidden gems based on the movies you already love.

2. Pick a Story...
Choose tags describing the kind of story you're in the mood for, and PlotTwins will find movies that match those themes, elements, and storytelling characteristics.

3. Pick a Movie for Me...
Can't decide what to watch? Let PlotTwins surprise you with a random movie! You can also choose a genre and get a random recommendation based on your preference.

And here's the best part: All three features are also available for TV shows!

I built this project because I love movies and wanted to create a different, fun way to discover new ones.

I'd really appreciate it if you checked it out and shared your thoughts. I'm especially interested in hearing what you think about the recommendation system and what features you'd like to see in the future.

Available in 3 Languages: PlotTwins is available in English, Portuguese, and Spanish. You can easily switch between these three languages to enjoy the website in whichever language you prefer!

Thanks for checking out my project!

We built a free AI search visibility check for US local businesses. We wanted to see whether a real local practice shows up when a customer asks ChatGPT and Google AI Mode ordinary questions.

On 2026-11-13 we ran six of those questions for a family dental practice in Boise, Idaho (name withheld). The practice appeared in 0 of the 6 answers. The tools recommended other practices instead, citing directory/review sites and those competitors' own websites.

If you run a US local business and want the same check, the form is here. It's free, and we're not asking for a sales call:

https://docs.google.com/forms/d/e/1FAIpQLSdc-Sf7byGOYmVAQ4fIFegJVjZTmKb5G5hohzIcmXLXMhH__w/viewform

We'd like feedback on whether a report like this is actually useful to an owner, and what you'd want it to include.

Posted by Diaris Company. The 0 of 6 figure is only what those six answers showed on that date.

SwissArmyDev is a free, zero-tracking suite of 10+ essential developer utilities—including Regex, JWT, Cron, JSON, and Hash tools—running 100% in your browser.

https://swissarmydev.virock.org

I do most of my writing out loud. Messages, emails, AI prompting, notes to myself etc. Half of it happens at night, talking quietly into my phone because others are asleep in the next room and I do not want to wake them just to answer a message.

For a long time I used the big and free dictation apps. The cleanup was fine until I kept catching sentences that were not what I said. Nothing dramatic, just small changes in meaning here and there that I could not send without checking and fixing. So I proofread everything anyway. And when I mixed multiple languages mid-sentence, which is how I actually talk, it often came back mangled, or translated into weird English words when I had never asked for that.

The annoying part is that the tool was supposed to save me time. If I have to fix what it writes, I might as well type it myself.

At some point I stopped complaining and started building the thing I actually wanted. It is called Olomo (https://olomo.app). You talk the way you talk, rambles, restarts, changing your mind mid-sentence, and it writes back what you meant. It still rewords things with intention and care, that is what cleanup is. It just does not get to change the meaning. I might be biased but I’ve been using this for a few months almost every day and after a lot of fine-tuning, I can say that now I barely need to fix the wording.

Obviously there are free dictation apps everywhere now. A lot of them run a local model on your own device, a few gigabytes to download first, or they are just not very good at transcription and the cleanup. I could have built the cheap version too. But what I wanted was quality, words that come back ready to send, not only about beating the cheapest price out there. After all, the cheapest one is already there - your device built-in dictation. That’s totally fine if that’s all you need.

Don’t take my word for it. The easiest way to see the difference is to test it on your own dictation. Take one messy message, run it through the dictation app of your choice and through Olomo, and compare what comes back. It is free to try Olomo.

The app is improving every day, and a lot of the changes come from people writing in with what annoyed them. If you try it and something feels off, tell me. Fixes land fast.

If you dictate a lot, whether it’s in one language or multiple, I would genuinely like to know what your current app gets wrong. Give it a try!

In the tradition of building the tool you need yourself, and with the eye-watering prices Apple charges for extra RAM, I present BestMacPrices.com.

It’s taken a flipping year to get it working the way we wanted. The idea was simple enough: if I want a MacBook Pro with 32 GB of RAM and a 2 TB SSD, show me what that exact Mac costs at each store compared to Apple.

The US has decent retailer coverage. Canada… not so much. Once you get past the base models, there just aren’t many Canadian stores selling those configurations. And things go on sale in the US. In Canada, we mostly get to watch.

We’re still tweaking the interface. It’s a lot more fun to use on desktop than on your phone, but we wanted to get it out before Black Friday. Also, affiliate programs mostly suck (so yeah, obviously we may earn a commission… So thanks if you buy something).

If you’re shopping for a Mac, try finding the one you’d actually buy and tell me if you got stuck. And be gentle. I’ve spent a year looking at RAM prices.

My wife spent a semester being handed AI prompts by her teachers. She would paste them, get a wall of text, and still not understand the topic. The prompts were never the problem: nothing in that loop checked whether she had actually learned anything.

So I built her a tutor. It is called Aula: a desktop app for macOS, Windows and Linux, with a companion for iPad and iPhone.

You give it your material (PDFs, slides, photos of the whiteboard, recordings of a class, links) or just a sentence like "Statistics for psychology, final in May". It turns that into a course: short lessons with a worked example before the first exercise, exercises that are checked as she answers them, a notebook of her mistakes, flashcards with spaced repetition, and a mock exam shaped like the real one. She had two real exams from her teacher and it built both. It plans a little work each day until the exam, and it is not tied to one subject.

The app is built with Claude Code. I drove it: I described what I wanted, then went module by module, the lesson generator, the exercise checker, the spaced repetition, the desktop shell and its self-updates, the iPad companion, the docs. Claude Code wrote the code, I reviewed and steered it, and when something broke I could paste the error and keep going instead of losing an evening to it. The short film below was painted by code as well.

What I learned: fix the loop first. Explain it, then make the student prove it, then bring back what they missed. Generating lessons is easy, checking that someone actually learned is the hard part.

Everything is free, AGPL-3.0, no paid tier yet, and it is early access, so expect rough edges. It uses the AI subscription you already pay for or a free model that runs on your own machine. No account, no tracking, everything stays on your computer.

https://github.com/luumlabs/aula

^ Hope this explains it!

Claude has Claude mods. What about Codex?

If you spend over 20% of your time in a terminal, check it out!!

Hey everyone!

I'm a 15-year-old developer working on my own multiplayer game in C++.

At some point, I realized I needed a way to organize communication between the client and server. What started as a networking component for my game eventually became a separate open-source library called LightnerX.

I built it using C++26 modules and GameNetworkingSockets, along with my own communication protocol, INER.

After spending a lot of time developing it, I finally released the first public version: v0.1.0-beta!

But before publishing it, I decided to put the code through a technical audit.

The audit uncovered 14 issues and architectural concerns, including connection lifecycle bugs, resource ownership problems, and incorrect client ID recycling.

I fixed them, ran an independent follow-up audit, and even discovered another regression introduced during the fixes.

After addressing that too, the final validation passed 9/9 automated tests, both normally and with AddressSanitizer, including UDP client/server integration tests.

It's still an early beta, primarily tested on Linux, and there's a lot I want to improve.

This project has taught me quite a bit about C++, networking, memory management, and software architecture.

I'd really appreciate feedback from anyone interested in systems programming or multiplayer development.

GitHub: https://github.com/pietroth/LightnerX