Kai Sing
Building tools for the web
Developer crafting Chrome extensions, games, and web experiences.
About
I build things that make the web more useful and fun — from browser extensions that streamline your workflow to games that bring people together. I believe great tools should feel effortless.
Always shipping. Always learning. Always otterly curious.
Projects
GoPDF
A modern, GPU-drawn, tabbed PDF reader for Windows built with Go and MuPDF (no webview). Instant open, low RAM with byte-budgeted pixel caches, and keyboard-driven: tabs, Ctrl+K command palette, thumbnail sidebar, and in-document search with highlights.
TokenBar
AI subscription usage monitor in the terminal and browser. Track OpenCode Go, ZAI, and Grok quotas with live color-coded meters, multi-account TUI, and a local mobile web dashboard.
Flip — 簡繁轉換器
Simplified ↔ Traditional Chinese converter with phrase-aware engine (tongwen-core), per-domain auto-convert, and full offline support. Optimized for Orion iOS.
Boost JS CSS Injector
Inject custom JavaScript and CSS into any webpage, per domain, in real time. Syntax-highlighted editors and mobile support, including the Orion Browser on iOS.
Command Palette
The Arc Browser command bar, for every Chromium browser. Search all tabs, windows, history, bookmarks and top sites from one keyboard-first palette with bangs and custom search engines.
Stream: Grok Prompt Navigator
My Prompts dropdown, one-click code-block collapse, and inline Chart.js rendering for grok.com chats. Native-looking buttons, no tracking, no network requests.
Flare — Ask AI & Web Copilot
Highlight any text on any website and ask AI in one click, with your choice of Grok, Perplexity or ChatGPT. Privacy-first: no API keys, no servers, no sign-ups.
Decrypto Online
Real-time multiplayer Decrypto for 4–8 players. Host a room, share a link, and race to intercept the other team's codes — Express, Socket.IO, and mobile-first UI.
UNO Rampage
Classic UNO reimagined with custom rules. Play your way with friends using configurable game modes and house rules.
OrthoGnomes
Turn-based 2-player abstract strategy game. Stack colored blocks on a 4x4 board to win the 5 orthographic projections — mobile-first Three.js.
Toolbox
A collection of client-side only tools built for developers and creators. Includes a QR Code Generator, String Formatter, Icon Resizer, and more — all running locally in your browser with no server required.
Let's Connect
Find me across the web — I'm always up for a chat about extensions, games, or anything web.