Browser Extension Builder

This one walks you through building browser extensions that actually ship, covering Manifest V3, content scripts, background workers, and Chrome Web Store publishing. You get practical patterns for extension architecture, injecting UI into pages, handling storage across devices, and the communication flow between popup, background, and content scripts. The anti-patterns section is particularly useful: it'll steer you away from requesting too many permissions (store rejection territory) and running heavy background processes that MV3 will just kill anyway. Good for building Chrome or Firefox extensions, whether it's a quick productivity tool or something you're planning to monetize. Comes with code you can actually copy and adjust.