I started lifting for self improvement and quickly got hooked on progression and getting stronger. It didn't take long to become a habit and now it's the thing I most look forward to after a long day of work. With no more than three hours per week you can completely transform yourself..
A lot of the fitness apps have tracking for weightlifting. You get a little badge or animation when you hit a new max.. I think there's a missed opportunity here for a weightlifting RPG like walkscape is for walking..