I have no insight into development, but I use Memmy on a daily basis. I feel like it hit the mark already and there really isn’t that much to do but maintenance work until Lemmy itself matures further.
The unknown errors are I think related to instance stability. The app itself seems fine.
There are still bugs that need fixing. The main developer seems to be taking a break, check the posts from GKD. Understandable and well deserved for all the good work he did, Memmy was the best app on IOS in my view and it made my move to the fediverse a better experience. But I am writing this using the Voyager app, I switched because of unresolved bugs (mainly comments not showing up depending on the sort option). I may return when development resumes.
I walked away from Memmy weeks ago and use Voyager now. Every single time I did a search for nsfw communities and scrolled down a little I could reliably crash it.
Either way, I’ve used Memmy since June including now and haven’t noticed any issues
If you browse using the web and also using memmy you will quickly notice comments are missing in memmy that show in any other app or the web page.