In my pocket is a small device that is a metronome, a tuner, a radio. A computer. It can transpose music to a different key. It is compass, a flashlight, a calendar, a gps device, an atlas, a clock, stopwatch and timer. A weather forecaster and stock ticker. A tape recorder. It could play chess if I wanted it to, or do countless other things. It is a video and still camera, a dictionary.
If I ask my students what their favorite app on their phones, they will tell me something stupid and silly. As though their favorite tool on a Swiss army knife was the toothpick.