I'm sure this is a perfectly fine screen recorder (though it's worth mentioning QuickTime Player has such a feature built-in), but I'm not sure why you'd want to record YouTube videos this way. Wouldn't it be much easier to simply download the actual video file using one of the many tools that are available?

I just have to say that I wish people would stop using App Store links and link instead to a program's home page. I am seeing this everywhere and it is annoying.

This Mac App allows you to take screenshots or videos of what is happening on your Mac in a pre-defined area. Super simple, super easy