Android (without F-Droid)
Web Browser
- Firefox free (MPL, GPL, LGPL)
- Firefox Klar free (MPL)
Browser Extensions
- uBlock Origin free (GPL)
- EFF Privacy Badger free (GPL)
E-Mail Client
- K-9 Mail (recommended) free (apache)
E-Mail Encryption
- OpenKeychain (for K-9 Mail) (recommended) free (GPL)
Messenger
Map
- OsmAnd~ (recommended) free (GPL)
Media Player
- VLC for Android (recommended) free (GPL, LGPL)
Podcast Manager & Player
- AntennaPod free (MIT)
File Managers
- FX gratis
- Total Commander gratis
PDF Viewer
- MuPDF Viewer free (AGPL)
Mathematics
- GeoGebra Graphing Calculator gratis
- GeoGebra Geometry gratis
- GeoGebra 3D Graphing gratis
pkpass Viewers
- PassAndroid free (GPL)
Public Transport
- Transportr (choose ÖBB for Austria) free (GPL)
- ÖBB Scotty (Austria only) gratis
What is the difference between free and gratis?
Free means free as in freedom while gratis only means that you don’t have to pay for it.