AT&T has stepped up its efforts to offload traffic from data-hungry Android smartphones onto Wi-Fi networks.

The operator today released its Smart Wi-Fi app in the Android Market. The free app helps customers locate and manage their various Wi-Fi connections and auto-connects to previously accessed Wi-Fi hotspots when they become available, shifting traffic off of AT&T's cellular network.

Android smartphones with version 2.1 or higher can use the app, which is designed to be used for U.S. hotspots, not international Wi-Fi connections. AT&T said it will expand the app to more devices in the future.

The app was designed with battery life in mind. AT&T says it has an "ability to sense when Wi-Fi is near," allowing the phone's power-intensive Wi-Fi radio to stay off until it's needed. AT&T's internal research found that customers who connected their phones with Wi-Fi wanted improvements in battery consumption and easier ways to find hotspots.

AT&T has been at the forefront of Wi-Fi offloading. It operates 27,000 hotspots in the United States and 190,000 hotspots overseas through roaming agreements. Most of its smartphone customers can access the U.S. Wi-Fi network at no additional cost, and Wi-Fi doesn't count against their monthly data plans.