I've been running this app on both my iPad and iPhone...
https://itunes.apple.com/us/app/lake...450383355?mt=8
Best $35 you can spend if you own either device and are on the lake.
This year I might invest in the Lifeproof Nuud waterproof case and a Ram mount for the iPad. I just purchased a bluetooth capable stereo and plan on using the iPad as a music server and Pandora streamer as well.
I feel like a shill for this app as I am constantly endorsing it on the forums.