I use ScreenFlow and I am an affiliate for the application. I paid for the application initially but I was pleased to get on the Beta program to get version 2 upgrade without having to pay for the upgrade. I have tried other screen capture apps such as iShowU and SnapzPro, both of which I also paid for. It was the fault of Don McAllister that I lashed out more cash to get ScreenFlow when I already had to screen capture applications. When I met him at Podcamp Barcelona he gave me the recommendation. I tried it and decided that buying it was a no brainer for what I wanted to do. So you can trust me when I say that if you have not tried it yet then I would say give it a try. Once you have made a couple of Screencasts with it you will want to have it past the trial period too.
Here is screencast in which I show you the basics of ScreenFlow. How to put in video actions and callouts and set them up to work and look right. I will do some more screencasts featuring ScreenFlow soon. Why not hit the Leave a comment button below and say what you think yourself. Looking forward to hearing from you.