If I developed an app that checks for its updates on f-droid.org without user opt-in will it get flagged for tracking?
No, F-Droid Client can check and update
No. I mean what if user downloaded the app from github releases and don’t have f-droid installed.
In this case I may check whether f-droid is installed or not.
and if f-droid is not installed I will check f-droid.org for app updates.
You can if it’s opt-in only.
I think you can also do it as opt-out, but then it gets the Tracking anti-feature: Anti-Features | F-Droid - Free and Open Source Android App Repository
But we only check f-droid.org and f-droid doesn’t track.
To me it looks like if you can do auto-updates but when starting the app first there should be a message like “This app auto-updates if no F-Droid is installed. You can deactivate this in → Settings → Updates”. Or maybe offer an activated checkbox “auto-update if no F-Droid is installed” at the start screen.
You can still keep the same idea of opt-in, imho, no matter where you check