RAY is a running application that provides real-time feedback on your performance. The app compares your speed with your previous runs and gives you an estimate of how much faster or slower you are. It also shows you how much you are ahead or behind where you were at the same point in the previous run.

The app is useful to know how much faster you are running compared to the previous time. Furthermore, you can see how far behind you were last time and how far ahead you are this time. If you are behind compared to your previous run, RAY will also show you the amount of time you were behind.