You can’t beat Song Rhythm Tracks! Try the Classic Country Music Sampler, https://itunes.apple.com/us/app/old-country-music-sampler/id1360761389?mt=8
It is a great way to get into using the backing tracks and the App with these pre-arranged numbers, http://alivedrumming.com/old-country-music-sampler-ios-app-released-by-alive-drumming/
“Old Country Music” Sampler iOS App released by Alive Drumming