A back button for when you're in the exercise itself.

The addition of integrated gps would be very useful for distance based workouts. Even the abitlity to have distance based workouts and enter distances manually.

The GPS feature would be for any exercises that could or should be measured by distance. For instance if you go for a run outside, instead of measuring the exercise in seconds (time), you could measure the exercise by distance. The future would require that you start the exercise and the GPS would run in the background, measuring the distance until you stop the exercise. Progress for such exercises would be measured in distance instead of time or reps. An alternative to that for this program would be to be able to use a third party GPS to determine distance and then enter it into this app manually. It just does not make much sense to measure a run or a walk or any other similar traveling exercise in seconds or reps.

I hope that clarifies my suggestion a little bit.

Having to move to, pick up and tap the phone every set is a bit clumsy.  I thought it would  be nice to have a button that would trigger the default action (next/finished).  Something like THIS.  The app would need to recognize the device, map to the appropriate logical button and respond within the current state of the application. 

Add an estimation of calories burnt after workout. Its been suggested quite some time ago so reposting the idea

Can the bell be changed to something that counts down? I rather like something that gives a little warning that time is about to end. In the past I have had the Olympic in the gate and go sounds as well as a voice count down.