Version 0.7.25 is installed on my 5800 and working well.
One gripe - when I first installed it, it pulled my contact list. I since trimmed down the contact list to make it easier to dial (there were too many, and the list was populated with blank identifiers). However, even after removing the app, and reinstalling - it holds onto the original contact list (and sign in info....). Any hints to fix this?
update - oops - Now I realize the GV app uses the phone contact list not the google voice contact list. So I'm a happier guy - but I'll leave the gripe here in case anyone makes the same mistake I did!

not a support question