The lack of UMA on Android devices might be an issue to some folks, but T-Mobile might be gearing up to solve that issue soon. Recent leaked pictures show that an Android Wi-Fi calling app will be arriving from T-Mobile, though it’s unlikely that it will appear in the Android Market and will instead have to rely on an OTA (over-the-air) update. Let’s not forget that the LG Optimus was recently pictured with Wi-Fi calling listed as a feature too, so things are looking up. The little bit of bad news comes in the form that there will be no hand-off, which means that if you leave the Wi-Fi coverage area, the call will drop. It seems that this feature will not be available to all Android devices, and only “select new devices”, which are speculated to include the Samsung Vibrant and upcoming T-Mobile G2.