Snrb Labs has the GrooVe IP in the Amazon Appstore for Android for $1.99 (4.99 – 3 instant savings) for a limited time.

This app, in conjunction with Google Voice, lets you make unlimited calls to any phone in the U.S. or Canada using the data connection of your mobile device (including Wi-Fi and/or 3G,4G) without using your mobile minutes. Once you get a free public phone number from Google Voice, use this app to make or receive calls to/from anyone in the world. (To learn how to get a free US phone number, low international calling rates, or any other details, please visit the Google Voice website.)

Enjoy a single number that calls you anywhere, online voicemail, free calls within U.S. and Canada, incredibly low rates everywhere else, and the ability to send incoming calls to voicemail. If you have a smartphone with Wi-Fi connectivity but no mobile plan, use this app to convert it to a free, full-featured working phone.

This app has a separate dialer that can be used to make calls. Alternatively, the native dialer, call-log, contacts, and favorite functionality can be shared between the phone and app on a call-by-call basis. Google Voice is currently only available in the US.