We used to use [YapDatabase] but [removed it in early 2021][1] after a
[migration to GRDB that started in 2019][2].
If you haven't opened the app since before we dropped YDB--in other
words, since early 2021--you'll see the following text on a screen
before you open the app:
> Because you've been inactive for a long period of time, you must
> register again to use Signal.
Tapping "Next" will send you into the normal registration flow.
I think this is a tiny number of users, so I removed this screen and
associated code. This will help simplify future onboarding code.
[1]: 86b8eb08b8
[2]: 2a5683b843
[YapDatabase]: https://github.com/signalapp/YapDatabase
c5a71adc06