So, a couple of years ago i set myself to find a simple program that could perform simple digital algebra operations. Eventually i found Logic Friday, which turned out to be simple to use, fast and powerful enough for simple problems. It is basically a GUI for espresso and misII and it works wonderfully. However it is only available for windows, so here is a simple Mac version of Logic Friday (thanks to Wine). I have tested it in multiple apple computers running 10.8 and it worked fine.
All the credit to Sontrak (where you can download the original windows version and obtain further information on the Logic Friday tool) and to the espresso and misII tools*
You can download the Mac version here: LogicFriday.zip (251.0 MB)
ALSO: Make sure that you have X11 installed in your Mac! It used to come preinstalled in OS X but not anymore!!!!
*Espresso and misII are copyright © 1988-1993, Regents of the University of California.