My Band is en route, but my understanding is we wont be able to do this until they release the SDK so third parties can add functionality to allow this.
I'm in the same boat for my gym workouts. I like to make my own workout routines and will have to make a choice soon - continue to carry my phone around so I can use GymAce (formerly GymPro) which is a fabulous app for tracking weight training workouts, and ditching my custom routines fir the loadable ones.
I need to review those before deciding for sure, since if they don't support tracking reps and weight, it's a deal breaker for now for using that feature.