Last September, T-Mobile USA said that the company does not intend on having UMA for Android devices. But T-Mobile had a change of heart,  announcing today that it will release an UMA-based Wi-Fi calling option on Android phones. This will be via an application released last month by Kineto Wireless, an UMA Vendor for T-Mobile.

According to sources, the Smart Wifi App from Kineto works exclusively on some versions of Android which is why it will not be available in the marketplace. Also, UMA on Android is distinct from the UMAs running on Blackberry and Nokia E73.

In the case of Blackberry, it has a system-level integration. The device switches on and off the Wi-fi network, draining battery easily. Chip level integration automatically switches from Wi-fi to cellular network. This will leave an advantage for the app-based UMA as it will go easy on the power.

It’s an important step for T-Mobile, one it’s been after for a couple of years now.  Finding alternatives for Wi-Fi communications gives the wireless service provider a competitive advantage during a time when airwaves and other form of network communications are bringing access to everyone with a connected device.

As T-Mobile gears up for another major product launch with Windows Phone 7, the company is sure to develop as much of a network edge as possible, even beyond Android.  When it comes to Android devices, however, T-Mobile has been taking great lengths to support Google’s OS, as it was the first to offer the smartphones when they emerged on the market about two years ago.