I haven’t tried it yet but I read in a similar post about Language Transfer.
It’s FOSS and they have an app. The languages are limited in number but most main ones are there (except Italian!).
It’s basically recordings of lessons that you pause and repeat back, which sounds crap but seems to be done really well. The recordings are stored on several platforms for preferred access.
It has a music theory intro as well, which is why I’m sitting on it.