OpenHub for GitHub - Fast and concise, open-source GitHub client app.
Synology Note Station - Without needing to spend money on Evernote, Synology Note Station provides a desktop client to organize all your random notes in one place.
Nullboard - Minimalist locally-stored kanban board / task list manager.
Pocket Lists - World’s Friendliest To-Do List App
Brisqi - Offline-first personal Kanban app
UpNote - A beautiful and clean cross-platform app for notes organizer