[feature request] list/track stale apps installed by f-droid

This is a feature request. Maybe related to #195 (closed)

What did you do?

Either one:

1. Install an app from an f-droid repository, then disable that repository (making the app unavailable). see #1073 (closed)
2. Install an app from f-droid, which then is removed from the repo (?)
3. Install an app from f-droid, which becomes unmaintained and/or replaced by another app(-id)

What did you expect to see?

f-droid should list apps gone stale that were installed through it.