This Mac application was originally produced by Jean-Louis Valero. The software lies within Audio & Video Tools, more precisely General.
From the developer:
LoopyLoopX is an universal multimedia reader with a text processor. The reader is very powerful... It can read all Quicktime formats (video and sound) & audio CD. Video can be full screen on the main monitor or a second one. You can play, pause, rewind and forward (from 1 frame to 1 minute steps). You can make a loop from A to B and shift it forward or backward. You can paste into the text whichever time, loop or file path.