This paper presents a seamless high-quality HTTP adaptive streaming algorithm that considers wireless network conditions and the energy consumption of a mobile device with networking cost constraints over heterogeneous wireless networks. In the proposed algorithm, the requested video segments are concurrently delivered through multiple wireless networks to overcome the limitations of a single network. The segment quality level, number of requested segments, network inactive interval, and amount of requested data through each wireless network are determined adaptively in order to provide a seamless high-quality video with low energy consumption and networking cost constraints at the mobile device. The proposed algorithm is fully implemented in an Android-based mobile device and tested in an actual wireless network environment.