iShowU has specified capture size - the user can easily specify the size of the video to be captured, using an intuitive 'see through' video preview. Just drag the corners around to specify the size, and hit enter. Fixed or follow mouse modes - Sometimes you'll want the capture rectangle (think of it as a movie camera that tracks your mouse) to follow the mouse, and other times, you'll want to capture just one area of the screen. iShowU can do both. User defined audio/video quality - While internet connections are getting faster, it's still going to take a while to transfer a 5GB movie to your Mum. iShowU compresses audio using AAC, and video using whatever method you think it appropriate (it defaults to H264). In addition, you can specify the quality of the video to your liking. Custom frame rates - When there's not much going on (i.e: you're not moving the mouse, just speaking) iShowU will capture at a lesser frame rate. When you start moving the mouse around (and the capture rectangle follow it) then it'll use a faster frame rate so that the motion looks smooth. Saves on bandwidth too. Simple - iShowU is designed specifically to be easy to use. If you don't want to customize anything, it'll work straight out of the tin. All you have to do is hit 'Record' and you'll have a nice little video on your desktop in no time.
What's new in this version:
Made a fix to workaround crash issues for users updating to 10.9.3.