I believe the airline can refuse you a flight if you don't have a return flight or onward travel, or a visa, otherwise you become their responsibility if refused entry
they even know your make , model etc of your phone too. And, don't forget, it listens to all your conversations when turned on, not sure about turned off.
he means you can get a statement emailed to you from the app. Im not sure if it works at all immigration offices though. I was told it wouldn't work at the one i use