Looks like T-mobile is out to prove it's still in the game, despite being purchased by AT&T. Based on this screenshot, starting today, you will be able to hold Wi-Fi voice calls for free. And oh yea, it's unlimited.
Wi-Fi calls used to be deducted from a customers minutes, which of course seemed like an unfair deal since you are actually using your own network. But perhaps in an effort to keep it's customers, the carrier is now offering it at no cost. The catch? You must be on an eligible calling plan and have a wi-fi capable handset to take advantage of the new feature. Those eligible will be receiving text messages in the coming days with instructions on how to enable the feature.