If you've got the MW600, you don't need any apps!
All you need to do is hold down the play button on the MW600. A picture of a phone and a radio will appear. Using the volume control, slide over to the radio. The radio will then start. Using the forward and reverse buttons on the remote to change stations - press and hold to automatically search, or just press and release to move up and down the frequency band.
It's all in the user manual!