Back-off sets!
Goto et al. (2004) studied back-off sets. They found that lifters who did back-off sets gained more strength and endurance than those who did not. There was also a trend (p = 0.08) for more muscle gain. Good news! Dr. Muscle now automates them for you. You'll do a back-off set on your last set whenever you have three or more work sets. This update also includes better looking exercise cards and pictorials, as well as easier and more frequent challenges.