I have a Samsung Galaxy S5 currently running LineageOS (without Google Apps).
- Social networking client. I use it with my GNU social instance.
- Podcast Player
- Barcode Scanner
- Barcode Scanner
Jabber (XMPP) client.
To connect to my Prosody server.
Contacts (CardDAV) and Calendar (CalDAV) sync.
I have it sync with my Nextcloud instance.
- Document Viewer
- Viewer for many document formats
- Catalogue of FOSS applications for the Android platform
- Two-factor authenticator
- Hacker News client
- Browser (Gecko-based).
- Synchronize remote ICS calendars to the native Android calendar app
- Infra-red remote controller for my Tv and soundbar.
- K-9 Mail
Supports PGP via APG or OpenKeychain.
- KDE Connect
- KDE Integration.
Remote control for Kodi — Open Source Home Theatre
I run Kodi on my Raspberry Pi.
- Lightweight YouTube frontend. I like the fact that you can send videos to Kodi through Kore
Manage OpenPGP keys
Integrates with K-9 Mail
It syncs to the ownCloud Tasks webapp via DAVDroid
- OpenVPN for Android
- Client to connect to my VPN server.
- Offline/online maps and navigation with OpenStreetMap
- View and upload files from/to my Nextcloud instance
- Practice Hub
Tools for musicians, including a chromatic tuner, a metronome, and a pitch drone.
I mostly use it to help me tune my guitar.
- Reddit client
- Revolution IRC
I use it with ZNC.
- GPS, sensor and network status
- Simple Last.fm Scrobbler
- A music scrobbler. Modified to submit to my GNU FM instance.
- Public Transport Companion.
- Terminal and SSH client.
Syncs with my wallabag instance.
- Wi-Fi Privacy Police
- Prevents your smartphone or tablet from leaking privacy sensitive information via Wi-Fi networks.
I use it with my instance of the μlogger server.