A terse run-down on how to get off the Google train, stop corporations Hoovering data from your phone, and all that (the story so far, at least...)
Root your phone and install a ROM
Search, App stores
On your phone, install the F-Droid app, it's an open source only app store.
Security and anonymity
IM, chat, Hangouts
On the server, install the Prosody XMPP server and create yourself an account. On your phone, install the seriously excellent Conversations XMPP client app - free on F-Droid, or a $3 donation on the play store.
Given the sudden recent resurgence and proliferation of a billion incompatible chat clients, both proprietary and various shades of open, the developer of Conversations has proposed OMEMO, an encrypted multi-user group chat protocol (using XEP-0163 PEP and Axolotl Ratchet) that is end-to-end(s)-, future- and forward-secure. It is currently supported by the Conversations XMPP app, and the proposed standard so new it doesn't (yet) have an XEP designation.
Roll your own cloud
There are open source projects you can run on a webserver for Dropbox-style file sync, photo albums, documents, etc., and they usually have their own sync apps that can auto-upload your photos and whatnot.
- Seafile is very robust, fast, and lightweight on resources. It can handle large volumes of traffic and file data without crapping out. It lacks a shiny web interface though. (app)
- NextCloud at version 12 has gained much stability, decent command-line server admin tools, and solved speed and security problems that plagued OwnCloud (and some frankly rather dumb design decisions). It has add-ons for photo galleries, calendar and contacts sync, playing music and video, video WebRTC and XMPP chat, LibreOffice Online integration, and more. (app)
Calendar and contacts sync
- NextCloud will sync your calendars and contacts using CalDAV and CardDAV. If you only want this calendar/contact DAV sync, you can instead install the lightweight Baïkal PHP application on your webserver, point Apache at it, strap on an SSL certificate and you're good to go.
- Export your contacts from Google/Facebook/wherever, and import them into NextCloud/Baïkal.
- On your phone, install DAVx⁵ and add accounts with your CalDAV and CardDAV URLs. Now your contacts and calendars will sync on your phone. Sorted.
More about calendars
Run your own mail server, and install: