How should I start building a camera and group-chat mobile app?

A web-based approach or WebView could work for a basic prototype if the app is not performance-intensive. However, camera access, push notifications, and home-screen widgets can be awkward in a WebView, so a cross-platform framework with native integrations will likely be easier as the project becomes more advanced.

Capacitor is another option if you want to keep using your existing web-development skills. It packages a web app as a mobile application and provides access to native features through plugins. Camera support may require some extra configuration, and you’ll still need to test carefully on both Android and iOS.

Since you already know web development, React Native with Expo could be a comfortable starting point. Begin with a very small prototype: take a photo, save or upload it, add basic authentication, and then build a simple group chat. Leave widgets and notifications until the main app works, because those features often require extra Android- and iOS-specific code. For the backend, Firebase or Supabase can provide authentication, storage, a database, and real-time updates without requiring you to build everything yourself.