F-Droid, the BEST app store to ever exist on android, ships only free (as in freedom) software, you can also enhance it by adding alternative repositories such as IzzyOnDroid and Guardian project.
Aurora Store (F-Droid) (Izzy), Free-software client to google play.
Privacy Browser (F-Droid), Webview based FOSS browser that disables features such as Javascript by default.
Orbot, TOR for android.
InviZible Pro (F-Droid), Combine the strengths of Tor, DNSCrypt and I2P for security and anonymity.
Newpipe (F-Droid) (Izzy), FOSS youtube client, also includes support for SoundCloud, Bandcamp, Peertube, and media.ccc.de.
Tubular (F-Droid) (Izzy), Fork of newpipe that adds features like SponsorBlock and ReturnYouTubeDislike.
PipePipe (F-Droid) (Izzy), Fork of NewPipe that includes support for NicoNico and BiliBili.
FreeTubeAndroid (Izzy), A soft fork of FreeTube which brings it to Android.
DroidFS (F-Droid), Encrypted filesystems on android.
KeepassDX (F-Droid), Keepass for Android.
If you have anymore recommendations, just contact me.