I can easily exit the app by clicking the home button and go anywhere I want to. The purpose of the app is to stop us from navigating other apps which I don't see getting fulfilled. I can Even go to tabs that I opened and didn't exit without my tree being killed. At first, I didn't know that it was that easy to fool the app,but after tad a bit of time,I realized that it was pretty easy to open youtube while my tree was growing and still ensure that my forest is lush and green. It's lame.