The Shack teams with Cricket for month-to-month plans ranging from $25 to $60.
The new UI adds features to Android for better user customization, notably the design and functions of the handset's homepage.
T-Mobile's latest myTouch phones are inexpensive, but don't have the most cutting-edge specs.
Analysis: Established vendors want to set their smartphones apart from emerging less expensive devices. But does reputation beat a bargain?