Name says it all. But in order for it to work it needs to be on charge so it can be stopped (when you stop charging it will stop.) if that doesn't work then your phone will need to be turned off. You will have to edit the "start app activity" block and put the app in there.
(I am not to be blamed for any damage caused by the flow. You have started the flow not me.)
Rate and review within the app in the Community section.