The controls for Pool Service are quite simple and easy to master.
Here are some notes to help you along.

In order to navigate to each section of the bowl simply tilt your device in the direction you want to go.

To perform a Grind, press two fingers down before you hit the lip of the pool. To switch to a Boardslide, simply lift one finger up while in a grind.

To perform an aerial trick, swipe your finger(s) up, down, left, or right while in the air. Tilt the device in the air to add a rotation