A super lightweight and low friction app for weight lifting that: - Lets you track workouts (exercises, weight, number of sets and reps, etc). - Suggests / coac

A super lightweight and low friction app for weight lifting that: - Lets you track workouts (exercises, weight, number of sets and reps, etc). - Suggests / coaches you on what exercises to do each workout, what weight to set, how many reps, etc. based on your progress so far in past workouts. - Acts as resting timer between sets and exercises (without having to switch apps or anything). Bonus points for some kind of alert (vibration? sound?) when you have say 10 seconds left. Bonus points for: - Automatically counts reps you do based on your arm movements, then starts the resting timer once you stop doing reps. - Accurately records your movement and later corrects your posture (say with squats, etc).