Has AnkiApp made any improvements to Anki, or it it pretty much just a flashier UI?

Ew, no. The fact that they are intentionally confusing users to piggyback off Anki's success is so scummy and distasteful.

If I'm getting this correctly, there is a flashcard app called "AnkiApp" that is separate from "Anki", but uses the same name. That's very misleading.