Hello, I'mBolt Guo.
I'm a frontend developer. I build tools that help me learn or solve a problem, and I usually handle the design and code myself.
Away from the keyboard, I'm playing games, watching anime, or making an already-long playlist even longer.
How I learn
I don't take notes. I build them.
Reading gives me the shape of an idea. It clicks only after I can change an input, step through the result, and see where my mental model breaks.
That's how a small binary-search demo turned into VizLearn. I took the same approach with my React and Vue notes: each concept became something I could run and inspect.
The bugs are useful. They show me what I don't understand yet.
What I ship
Most projects start with one annoyance.
Sometimes it's a watermark I want to remove without uploading the image. Sometimes it's a QR code I want on my Lock Screen. I build the smallest useful version first, then see if the idea deserves more.
I take each project from interface to release myself. After living with it for a while, I keep the parts worth maintaining and cut the rest.
If a project solves the problem and has nothing else to prove, I leave it alone.
What I've built
Projects
Two projects I'd show you first.
VizLearn
Change an input and step through what happens next. The code, visualization, and execution log stay in sync, so the result never feels like a magic trick.
Free to use in the browser, with lessons on algorithms, AI, and computer science.
Open VizLearnKanaPlanet
I couldn't find a Japanese-learning tool that felt right, so I built the whole thing: CSV as the content source of truth, TTS audio, KanjiVG stroke order, an SRS review engine, pronunciation scoring, and AI conversations for real-life situations.
It doesn't promise a test score. I built it to help me actually use Japanese. One Expo monorepo compiles the same application logic for two targets: a native iOS app and a web app deployed to Cloudflare's edge. A local-first data layer keeps them in sync.
Open KanaPlanet
More from the workbench.
- Watermark RemoverRemove Nano Banana watermarks in your browser by reversing alpha blending. Your image stays on your device, and no AI tries to guess the missing pixels.
- CodePinMake a QR code or barcode, or scan one with the camera or from a photo. Keep it in history, pin it to the Lock Screen or Dynamic Island, and export it as HD or SVG. Pro sync uses your private iCloud database.
- AOUO (Pre-alpha)A pre-alpha take on local-first agent apps. Each .aouo pack keeps its skills and data inside a separate app boundary, with its own schedule, permissions, and UI.