That's nice, but AnkiDroid and AnkiMobile are different things. The former is a complete FOSS implementation of Anki for Android, whereas AnkiMobile is a proprietary companion app to Anki from the Anki author (I think, iOS only).
I didn't know that, I only use android so I did not notice you had another app on iOS. Maybe the one I tried was called AnkiDroid then? I can't remember.
I'm using a completely non-Anki based flashcard app just because of the lack of this feature.
They can exchange data. Years ago I used Anki to prepare some decks which I then used with AnkiDroid.
I think AnkiDroid is mostly written in Kotlin now.