This is a great feature on Android which I'd like to replicate on the iPhone if possible. The Android Google Voice app has an option to "make only international calls" using Google Voice, which when you enter a non-U.S. phone number into the native dialer, automatically calls using Google Voice.
Currently on the iPhone I have to open the Google Voice app manually to call international numbers.
Currently on the iPhone I have to open the Google Voice app manually to call international numbers.