Allow us to add a particular exercise from another day's workout to a different workout
for example, adding the leg press from Tuesday's leg day workout to Friday's leg day workout.
John Altmix commented
I do that all the time on the Android phone app. I have two trainers, so I just put the exercises I did with my second trainer on a given day into an existing workout to track everything. You can even create your own exercise if it doesn't already exist.