GPS Phone Silencer v1.4 has been released.  This new version allows you to set your ringer (On/Silent/Vibrate) depending on Wifi connections.  Have a Wifi connection at work?  Set your phone to automatically go on Vibrate when you are connected.  Set your phone to be on ringer when you are disconnected from all Wifi networks (like in the car).

Download it now in the App Store.