Indispensable Business App.

This is a rock solid VoIP app. I use it to manage two additional numbers (office extension & 2nd personal line for long distance calls). I purchased the G729 codec pack for improved voice quality over 3G. This app is worth every penny if you have multiple lines and require such features as call-waiting.

ambsace about Groundwire: VoIP SIP Softphone, v1.5