This app helps you to brush your teeth. It visually and by vibrating shows you when to switch to a different section of your teeth to help you to brush your teeth as efficient as possible.
Mainly your bite is separated in top and bottom. Each of these are separated in front, middle and rear. These again are separated in left, middle and right. You propably understand this best by just trying the app out.
By default the time for each section is set to 7 seconds. You can change this by pressing the button "Change time". For example 7 seconds is the minimum time span with 2:06 minutes while 10 seconds the maximum time span with 3:00 minutes.