I have been using LineageOS, an open source fork of the Android operating system. My goal (which I think I'm pretty close to) is to use LineageOS as my daily phone, and reduce my reliance on Google etc.
I've found it incredibly refreshing, though it takes a bit of work to get it working, and it's much easier on some phones than others (and impossible on some).
There are numerous complementary and overlapping software projects. I'll list them here for reference.
# Non-Google on mobile - The Free Software Foundation Europe has an excellent overview of the options for free software on your phone. (They are pretty pure, so it doesn't mention options like Open GApps, Brave web browser, Aurora Store, or YouTube Vanced.) Free Your Phone - LineageOS has roots in CyanogenMod, and is the main open source fork of Android. It is not *entirely* free software (drivers and so forth); for the most free OS you'd want Replicant. - Multimedia options: NewPipe is a fantastic lightweight YouTube client. There's also YouTube Vanced, as well as YT Music Vanced, which offer a more Google-like experience of YouTube and YouTube Music with greater privacy. VLC player is a great standalone video player, and there are nice, simple music players like Vanilla Music. - NextCloud looks well worth exploring, but I'll have to install a dedicated server. Allows you to provide your own services for things you'd otherwise need proprietary software like Google Drive or Skype for. - MicroG is a free/open source re-implementation of Google's proprietary libraries etc. For reasons I'm not clear on, LineageOS has rejected it as a core part of its distribution, but it's possible to install a version of Lineage with MicroG. (I have not yet tried this.) microg.org and this 2021 review . - Open Gapps is a way to use Google apps under LineageOS. It's not a reimplementation, but rather a way of installing native Google software. I have not yet tried this either. OpenGapps.org - F-droid is an alternative to the Google Play Store. It is one of my favorite things these days. It has (mostly) only free/open source software; it also has software that tests the limits of such definitions. But where it really shines is, it clearly explains "anti-features"; if there's something (e.g., privacy insensitive) that they think you won't like, they explain it. - Aurora Store: This is more or less a "clone" of the Google Play Store. It's a way to install stuff from the Google Play Store on LineageOS. - Magic Earth: Apparently a very good free replacement for Google Maps. website
# Issues to resolve * How can I use Google Voice? Will it work with Open Gapps? (Seems likely, but oddly it is not listed on any of the official lists of what's included.) With MicroG? (less likely, probably buggy if at all.) Can I settle for SMS forwarding to email? * My first effort to install Open GApps has been a bust. I'm getting a weird error (Error 70) that claims there's not enough space on my /system/ partition...but I don't think that's true. Documented in more detail here . * Is the MicroG included in the Vanced packages superseded if I install MicroG at a system level?