TuberNotes

Chat Sidebar + Magic lasso
Homescreen

Inspiration

This app was made out of spite. GoodNotes is the best and most popular iOS pencil notes app. It is also franky, an unconfigurable $28 piece of sh*t. As college students who've spent 9+ hours a day in that app, screenshotting broken PDF renders and pasting them into ChatGPT, we decided to do better.

What it does

It's an open-source notes app with a magic lasso that summons frontier OpenAI models right into your page to interact with it. We mirrored OpenCode's implementation, so you can log in with OpenAI SSO and leverage GPT-5.6 using the ChatGPT plan you already pay for, without paying an extra dime. It's a good notes app, but what makes it "gooder" is that it's free.

*Free if you're already paying for ChatGPT :D

How we built it

Short answer: With Codex. Long answer: Agentic development is VERY good at easily unit-testable tasks. "Does the lasso feel right?" is not one of them. Our answer was an MCP tool for "taste" that queued a review request straight onto a physical iPad, blocked, and waited for a verdict from a human holding a Pencil. That single rule is what kept four autonomous agents from confidently drifting the app into garbage.

What we learned

Merging four agents' work is genuinely hard. Worktrees multiply and permanent documentation of design is more of a suggestion with GPT 5.6 and merges. The fix isn't better prompting, but in setting solid CI for Xcode compilation checks, computer-use simulator tests, and even human review.

What's next for TuberNotes

Open beta! If you want to be on our test flight, contact us at thephilliplin@gmail.com. If you have ever wanted something from a notes app, our promise is to give it to you.