English in Settings menu nits
General Settings typo
incoming calls form unknown contacts ->
incoming calls from unknown contacts
The only other thing that looks a bit vague is Advanced -> "Registration Expire" which I was a little afraid to click on in case it was short for "force registration expiration" instead of "Registration Expiration Time (seconds)".
I don't think either is likely to cause any actual problem, they just might give an initial impression of a less complete/popular app.