i had been doing calcs myself until january. i had tried multiple trials of different software. i settled on ibrewmaster for my iphone. i like it because it allows me to play with recipes on the fly. i can also share when i run in to other brewers. it does most of what i would want and more. i still idiot check the numbers.
I really like iBrewmaster as well. I started with ProMash years ago but iBrewmaster does everything I need plus I can have it running during my brew day on my iPad.