Tap Tap Counter

This is an excellent app for keeping track of something/someone in large quantities without having to remember which number you are on, with the added benefit of doing so discreetly.
 
Examples of uses may be:  making a guest list, counting large amounts of money/change, gathering test samples for experiments/surveys, listening for the number of times something is uttered (for correction of speech impediments/frequent use of a conversation tic, ex:  "um", "uh"), counting votes, or counting heads at a gathering.

A sleek counter that enables keeping track of counts forward or backwards, and allows you to start over to zero.  

Tapping the screen anywhere triggers the counter to increase (or decrease).