While I can't use Google Voice myself, I see a lot of positive feelings for the service online. And now the Android app will be getting just a little bit more approval thanks to a handy addition: billing history.
If you use Google Voice for placing calls, you'll be able to track your available credit through the app's Settings > Billing history. There, you'll find your recent activity with each call, its date and time, duration, how much it cost you, and your balance after it was over.
The changelog only mentions the new billing history and bug fixes, so it doesn't look like there's anything else that's changed. You can grab Google Voice 5.5 from the Play Store at the widget below, or directly sideload it from APK Mirror.