@lertsenem have you looked at the anki app lately? its developed in 1990s style. its much easier to start a new project then try to modernize that code. The course material could definitely be reused though and that could use an issue filed.
@liaizon I use the AnkiDroid app and I honestly find it better than Duolingo, with statistics, the possibility to learn more than just new languages, adjusting the repetitions as I see fit, adding my own cards, etc. It may gain from a little UI revamp, but feature-wise I don't think it's missing much.
I hope this new soft will just be a modernized Anki client using the same cards data. Maybe add federation for easier cards exchanges? :)
This is a private instance. Sorry.