Pop time is the time taken from the instant a pitch hits a catchers glove to the moment it strikes the glove of the middle infielder at second base. Good pop times range about 2 seconds, while great times would be around 1.8 seconds.
This app will help you easily keep track of the times on you iPhone or iPad. It will give you quick reports on Average Time, Best Time and Worst Time. It can also send you a spreadsheet of all times recorded for use in external apps.