Good news for F-Droid users. We're finally getting updates of our app on F-
Droid again. 
This apk is similar to the production apk on Google Play Store, and has the
same application ID. The flip side of that is that you can have only either
the F-Droid or the Google Play production apk installed at the same time.
The certificates used for building are different from ours, so to update
the apk you have to stick with the same line of apks, either from F-Droid or
from Google Play.
The only difference to the Google Play versions are channel name ("fdroid"),
version name (2.y.z-fdroid), and timing of releases. Other than that they
behave the same.