The Sound Bar Controller app provides easy operation for select Yamaha Sound Bars using your iPhone, iPod touch or iPad. Key Features: - Initial setup of built-in Alexa voice control settings - Basic control functions such as volume up/down and input selection - Play audio files stored on your phone or NAS drive through Wi-Fi - Volume control for wireless surround speakers and wireless subwoofer (Only SR-X40A, SR-X50A, ATS-X500) [Supported Models] YAS-109, YAS-209 ATS-1090, ATS-2090 SR-X40A, SR-X50A, ATS-X500 [iOS Version Requirement] * This application supports iOS version 10 or above. - A wireless Local Area Network (LAN) and a compatible Yamaha Network product(s)* residing within the same LAN.