The circles which are only available on iPad allow you to change a group of activities, medications or procedures to start at a different time - Change Frequency, Move Highlighting or Delete them (instead of deleting each one individually).
To do this, go to the Edit Mode and select the circles next to the treatments you wish to change/remove (you may choose just one or as many as you need):
OR
Click on the circle at the top left (beside the time) and select all treatments:
Once you have selected the items you would like to change then choose either Change Frequency, Move Highlighting or Delete option.