I'm creating a leangains diet planner and exercise+nutrition recommendation system. I'm nearing the end of my cut, during which I've lost 15 pounds and gone from 20%-13% bodyfat in about three months with significant strength improvements. After I'm done I'll go for a few months bulking while I finish up the documentation (lots of scientific studies to comb through!) and then I'll be launching. I use the software I've written for it everyday.