Speedometer Tiny
A tiny GPS speedometer: your speed in big legible digits, a live history chart, and a fastest tracker.
This one is exactly what the name says. Your speed, read from GPS, shown in huge monospaced digits you can read at a glance, with a little rolling chart of the last minute underneath and a record of your fastest speed at the bottom. You can switch between mph, km/h, m/s, knots, and even Mach, if you’re feeling ambitious.

The detail I’m quietly proud of: when GPS drops out, it falls back to the accelerometer and pedometer to estimate walking speed, so the number doesn’t just freeze. Small, but it’s the kind of thing that makes an app feel finished. It was a good little exercise in CoreLocation and in making one number look really, really good on a screen.
Find it at speedometertiny.com.