Print Center
Thanks to the iPhone’s AirPrint feature, you can instantly print on any printer that supports this feature with a few taps. But the Print Center app is really cool because it’s the only one you can’t just open by yourself. Instead, you can only access it you’re already printing something.
While you’re printing, go to the App Switcher, and you’ll see the Print Center app at the front of your apps. You can use it to see the print summary and how many other files are left to print.