In December 2016, about the same time I ditched Apple in favour of good old FreeBSD on my laptop, I gave my mother my old iPhone as a Newtonmas present. To replace it I bought myself a Nexus 5x and immediately installed CopperheadOS on it. It has served me well since then.
Installation of CopperheadOS was a breeze. Tools such as
adb was readily available as FreeBSD packages that was easily
installed on my Thinkpad without having to install a humongous Android
Studio or a huge Android SDK or anything.
Copperhead keeps a fork of Signal called Noise in their F-Droid repo. At the start, this was necessary since the Android flavour of Signal used Google Cloud Messaging to push messages. The Noise fork instead keeps a websocket open all the time. Bad for the battery, perhaps, but keeps you free from the Google services.
The upstreams Signal has since been patched to do the same thing, but you'll have to install it from the APK since it's not available on the F-Droid repo.
The Conversations XMPP client also keeps a connection alive all the time, but my battery time has been quite acceptable.
The F-Droid package repo is excellent. The FLOSS scene on Android is so much better than on iOS, where almost all free apps are closed source and many have advertisments. Some of the apps I use besides the built-in in Copperhead apps are:
- Conversations - XMPP client. See the Legacy version if you need OTR support. The new version only allows OMEMO and, strangely enough, PGP!
- AnySoftKeyboard - Keyboard replacement.
- Feeder - Really nice RSS/Atom reader.
- AntennaPod - Podcast client.
- NewPipe - Youtube client.
- Orbot - Tor connection.
- Pretty Good Music Player - very simple music player.
- Yaaic - IRC client.
- WiFiAnalyzer - Great way to see what's in the air.
- Maps - Offline maps from OpenStreetMap based on the MAPS.ME project. Much better than the OsmAnd+ I used before.
- Calendar - a calendar that I like much more than the built-in Etar.
- ForRunners - a tracking app for runners which, unlike most of its kind, doesn't report your location to a server somewhere.
I don't do e-mail on my phone. If I did I would probably use the K9 e-mail client.
My work phone is still an iPhone and thoroughly connected to both the Apple and Google universes, but it's nice to think that at least my personal phone is free from them.