If you have both a Raspberry Pi and an iPad, this tutorial from What a Palaver's Angela Wolff will help you remotely control the Pi with your tablet -- from anywhere you have an internet connection. Wolff offers the commands and instructions to set up the Raspberry Pi and iPad for perfect harmony.
She uses three iPad apps to do this: Fing (a free network scanner to find the Pi's IP address), Web SSH (also free, to connect to the Pi securely via SSH) and VNC Viewer ($US9.99, to replicate the Pi's graphical desktop). You could use other similar apps; perhaps experiment with one of these VNC apps for the iPad to save money.
You'll also want to check out the link in the comment by warriorwoman if you want to access the Pi from outside your network.