I've had BlueSound wireless hifi speakers for some time. Originally the control app was also capable of adjusting speaker volume with the volume buttons on your

I've had BlueSound wireless hifi speakers for some time. Originally the control app was also capable of adjusting speaker volume with the volume buttons on your phone, which I quite enjoyed. It was deprecated (along with the ability to play your iPhone's music library over wifi.. à la airplay) several years ago, presumably due to patent/licensing issues.