‘Apps’
It’s difficult today to turn on the television or browse some websites and not hear or see mention of apps. What are these things? Where did they come from?
I find the history of the word interesting. I’ve linked there to a picture of the precursor to Mac OS X: OpenStep which was originally called NeXTStep, the OS for Steve Job’s earlier computer, the NeXTStation/NeXTCube, etc.
As you can see here, the applications (i.e. programs, executables) are followed the extension .app. In fact, on a modern Mac, your applications are also labeled the same way, although you may have chosen to keep the default setting which hides this extension.

So, this is where the extension or label or name comes from: NeXTStep executables. Then the full name got dropped (perhaps because they’re small?) on the iPhone. And now more smart phone manufacturers are talking about apps.