Upgrading your plan may be a good way to avoid overage charges, but Sprint might have another option: WiFi calling. According to documents obtained by Android Central, the carrier is poised to give select Android phones the ability to call and text over a local connection, similar to T-Mobiles service. The Samsung Galaxy S4 mini and Galaxy Mega are reportedly the first handsets that will have access to the service, but itll also be available to future devices running Android 4.2 or higher.