Recently I was speaking at a PMI conference in Raleigh and a guy came up to our booth who noticed that I had an Android phone. We started talking (excitedly - like the geeks we are) about our favorite apps and he introduced me to SwiftKey - his favorite phone app of all time.
After downloading and playing with the free version for a few minutes I'm impressed. This thing is kind of clairvoyent sometimes. Word prediction is the name of the game. Sometimes I can type out most of a text message without doing anything but accepting the next word it predicts I'm going to type. It's really quite impressive.
There are many phone apps out there, some of them pretty inane.