You don't need to download a cat. They distribute themselves very well. It's a feature. Try walking around with psspsspss coming out of your mouth and fancy snacks in your pockets and see what happens.
That's a bit pedantic. App is used interchangeably to represent the whole platform.
I work as a SWE in a team with 15 year veterans at an App company that is a top 10 most downloaded on Android/iOS. We still use the word app this way in tech meetings.