You can’t beat Song Rhythm Tracks! Try the Afro-Cuban Sampler! https://itunes.apple.com/us/app/afro-cuban-salsa-sampler/id1367015786?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/afro-cuban-salsa-sampler-ios-app-released-by-alive-drumming/
“Afro-Cuban Salsa” Sampler iOS App released by Alive Drumming