Last week we heard from EE that it was beginning trials of mobile voice calls over Wi-Fi with a plan to launch the service fully later this year, and rival network Three is also getting in on the action.
The data friendly carrier has launched its beta "inTouch" service, allowing customers to make calls (and send/receive texts) over a Wi-Fi connection, although its implementation isn't quite as seamless as EE's plans.
Only Three customers who are experiencing serious issues with signal at home can currently download the app (on a compatible handset running Android 4.0 or above) to make calls over their wireless internet connection - similar to O2's TuGo offering.
EE's solution doesn't require an app, with the carrier automatically switching between mobile and Wi-Fi signal so you can continue to use your phone's dialler app as normal.
Three expects the final version of inTouch will be launched in August when it will also be available on iOS.