You can also have it run through more of a 'class' structure by going through a multidude of times such as 1min, 5min, 15min, etc. You can set up the timing in tons of ways, for example you can set it up to change references every 30 seconds, or minute, if you're practicing quick gestures (or any custom time).
This program let's you load reference photos that you have stored on your computer and then randomly cycles between them in a timed fashion so that you can draw from them.
This program is not just for Gesture Drawing, btw.
Omg I forgot to mention this in my last comment and this is quite possibly one of the best tools out there!
