littleBits o21 number

I clipped this onto the end of a light sensor chain to watch the readings change in real time, and it's surprisingly satisfying. The digits are big enough to read from across the table, which makes it handy for counting reps during workouts.

My kids use this number bit as a scoreboard for their little marble run game, and it's way more fun than keeping tally on paper. It picks up the count straight from the sensor bits before it, so nobody has to argue about whose point it was.