Ur Dice

This app is a dice roller for The Royal Game of Ur. Ur uses four two-sided dice that can each roll a 0 or a 1. This gives you a result between 0 and 4 with a unique probability distribution. It's easy to draw an Ur board, and to find small objects you can use as game pieces, but since 0-1 dice aren't common, this makes playing tricky. Flipping a coin 4 times takes too long. You can use any normal polyhedral dice and use odds as 0 and evens as 1, but this makes it hard to tell what you rolled at a glance.

This app is the solution. Launch in fullscreen and place the phone on the table between the two players. Each player has a button to press which will clear the screen and roll four dice with an easy-to-distinguish display.