well i use two right now.
Nobex radio companion.
Iheartradio.
There is also...
Slacker
Pandora
Just keep in mind u should have either an unlimited data plan or min of 2-3gb of data to avoid extra data charges.
There is also FlyCast 2.0 but it has never worked on my phone. So try to find 1.39 or whatever the last version was. That works just fine and in fact has more options then 2.0 which is a disaster all around.