The Merlin BeatMaster App is designed to pair with the Merlin BeatMaster boombox speaker,a combination LED light and Bluetooth speaker.The Merlin BeatMaster App gives the user full control over the Music Play,Light change,equalizer,USB/SD card play and Line In play.It provides the ability to control and adjust the volume,brightness,flash light modes of your Merlin BeatMaster boombox speaker as same as the remote control.