Speedometer (such a unique name, I know) is a basic, no-frills speedometer. It supports mph, km/h, m/s, and Mach (just in case.)

Stackulator is a minimal postfix calculator for Android.

With its beautiful design and streamlined interface, you’ll soon fall in love with math again. (Provided your math is simple, of course. You can’t expect a calculator to do complex math, can you?)

Autogyro locks the orientation of your screen and lets you control it from anywhere.