DEPRECATED: How to connect Firefox for Android to self-hosted Firefox Account and Firefox Sync servers
Firefox for Android version 33 and above support connecting to self-hosted services. Firefox for Android 44 and above no longer require an addon to connect to custom Firefox Account and Firefox Sync servers. The documentation at https://docs.services.mozilla.com/howtos/run-sync-1.5.html and https://docs.services.mozilla.com/howtos/run-fxa.html has been updated and is now the canonical documentation for configuring custom servers in Firefox for Android.
This deprecated post includes background and a detailed step-by-step guide showing how to connect Firefox for Android 43 and below to self-hosted Firefox Account and Firefox Sync servers.