LG Motion Keep Rebooting (Boot Loop) After Installing Beat Audio Installation
You could try booting into Safe Mode (according to this article you should be able to do so by holding down the Vol - key while switching on the device with the Power button).

In safe mode, all user-installed apps are "disabled", so they won't be started automatically. Once in safe mode, remove the troublesome app (uninstall it via Settings &rarr; Applications &rarr; Manage Applications). Then simply reboot to leave safe mode -- your device should now boot up fine.