joplin
By @Laurent Cozic
Joplin - the secure note taking and to-do app with synchronisation capabilities for Windows, macOS, Linux, Android and iOS.
android open project
By @Trinea
A categorized collection of Android Open Source Projects, More powerful web version:
spotube
🎧 Open source Spotify client that doesn't require Premium nor uses Electron! Available for both desktop & mobile!
uno
By @Uno Platform
Build Mobile, Desktop and WebAssembly apps with C# and XAML. Today. Open source and professionally supported.