"The tablets are dead useful, and indestructible," Jenny replied, nodding. "They have a map and everything."

Reaching over to mess with the Doctor's tablet, Jenny pulled up different functions -- text, voice, video, and then the map -- in rapid succession, trusting that her father could absorb the information in heartsbeats. The tablets were designed to be intuitive, and the Doctor could have figured it out on his own, but showing him was just that little bit much faster.