Tap 1 to begin — find every number in order
Tap 1, 2, 3… all the way to 25, in order, as fast as you can. Every wrong tap adds a +1s penalty. Lowest time wins.
Number Rush runs on the old Schulte grid trick: find 1 through 25 in order, as fast as you can, with a full second added for every wrong tap. It sounds like a kids' puzzle until you actually try to do it quickly. Free to play, no download.