Google Voice for Android has been updated to version 0.4.2.80 and brings improved reliability of SMS delivery along with other changes and improvements. Google Voice for Android lets you make cheap international calls with your Google number. Send free text messages. Place calls and send text messages showing your Google number. Listen to voicemail and read transcripts.
You can download the update directly on your device through the Google Play Store or by using the link which follows:
While the update to SMS reliability is warmly welcome, Android Police have also discovered an addition in the APK code which allows other apps to check on the Google Voice configuration settings. While it isnt clear what this functionality will be used for it is assumed it may be linked to Google's upcoming unified messaging platform - Babel.
source - Android Police