A good gym app with targets. iStayFit is what I used on the iphone. Far from perfect, but it did the job. I've got about every gym app loaded on my droid but none really do what I need them to do. I like to right down my workout with weights and reps beforehand, then workout with those weights. If I fail to complete a set I'll mark that down. If you want to get really specific, I'd love an app that is based on the Starting Strength program. Here's an excel file with several different version developed based on the program. Pretty much all of the calculations have already been done so might save some time for the right developer. It's been too many years since I've done any programming (Fortran, C, C++ and Java in college) so I doubt I'll attempt anything.