For a list of changes between versions, see here.
For a list of frequently asked questions (FAQ), see here.
I hacked this together for my own use, but perhaps you might find it useful too.
Many thanks to Evan Charlton for the original GV app, which he stated that he is no longer maintaining.
My app does not have most of the functionality of GV which are replaced by the official Google Voice app; instead it does something that is missing from the official Google Voice app: callback.
For those of you using gizmo5+sipdroid, this will come in handy as the calls connected through callback does not have the 3 minutes limit. And for those of you taking advantage of MyFave (or equivalent), this can make sure that you are always talking to your your google voice number!
Several bugs/annoyances from the original GV app are fixed/changed:
* fix problem with gizmo5/sipdroid
* connects only when internet is available
* can ask for every call whether to use GV
Enjoy! Let me know if there are bugs (and the must be! The app is not well tested yet).
If you appreciate my work, consider donating!