Essentially you touch the screen in different places for different vibrations. You can touch more than one place and create patterns. It comes with some presets as well. The app is...alright. It's more of a novelty. It's almost impossible to sit there and control it via the app because it requires a lot of patience, in my opinion. Plus you need both hands to touch multiple places. At least I do, but keep in mind I'm clumsy. You can always hold the vibrator in your lap and preset patterns with it that way, in which case it may be useful. I never really use the app. I just wanted to say I had it.
. This is my review on the NaughtiBod. It has screencaps and info on the app. It's not a ton of app detail, but it should give you a good idea of how it works and what it looks like.