Professional Software Corporation has been creating and selling child support software for quite awhile. My guess is that their software program is the most widely used among private practice attorneys.
They have released a free version of their software as a stand-alone page
. While it does not appear to be able to create worksheets for court use, it is very handy for quick calculations. The support amount automatically adjusts, and all of the inputs are on one page. Check it out here
. I have also linked it along the right side of the blog under "resources".
Since it is web-based, and all the inputs are on one page, it works perfectly from a mobile phone.