A look at a piece of the initial functional specification. This is about content only, I won't bore you with the technical implementation details.
Raw Routine Selection
Routine Selection Based on Goal
Auto-track via GPS for running/biking/hiking
Template driven for weight training
Free form journaling
Dietary and Supplement Advice
Basic information on common diets and supplements
Links out to forum where users can discuss in more depth
Share workouts with friends
Post workouts/pictures to Google+ or other venues
I like the ideas coming in. Keep them coming!
One of my sincere hopes for this app is that it will be something I personally could use. There's no good reason to limit the number of sets people can log, to not allow comparisons of previous workouts, etc except for lazy programmers or people who fundamentally do not understand fitness.
I think it might also be fun to include graphs to track progression on lifts, both weight and percentage based to compare progress with other lifts as well.