My wife had it installed on her phone for a while.
Over the last 15 years or more, her gang of 3 South Welsh ex-pat valleys girls
[if the Bristol Channel counts as overseas..]
have had occasional fits of enthusiasm to try to learn their native language..

Last time they tried Duolingo for a while until the novelty faded.
She reckoned it was a fun app, but when it was necessary to update
something about it seemed a bit off,
so we uninstalled it.
If I remember, it demanded for too many intrusive permissions...???