Simon Grimm is a German developer and educator behind the Galaxies.dev teaching platform, focused entirely on cross-platform mobile development with Ionic, Capacitor, React Native, and Flutter. He is one of the longest-running independent instructors on the Ionic / Capacitor stack and a frequent speaker at the framework's official events.
His CourseFlix listing carries over twenty Galaxies.dev courses covering Ionic Angular, Ionic React, Capacitor native plugin development, React Native, and Flutter — plus the surrounding ecosystem (auth, push notifications, in-app purchases, Stripe integration). Material is paid and aimed at developers building production mobile apps with web technologies rather than going down the native Swift / Kotlin track.