Click on the blank space. The default test time is 20 seconds and the default refresh time is 2 seconds. You can change the refresh time using the variable "seconds" and you can also change the test time with it. However, changing the "rpt" and "seconds" variables can further manipulate the test time. The top right variable shows your current clicks in the 2-second test margin, the top left variable shows how much time has passed, how many seconds you have left, and how long the test is, the bottom left variable shows your rounded average clicks per second(after the test), and the bottom right variable shows your accurate average clicks per second(after the test).
