What does printer apps do?

[MacBH928]

So Apple has Printer Pro as their free app of the week and I also downloaded HP All-In-One printing app but I don't know why should I use them?

Most if not all apps on iOS has a "print" option built in them like Dropbox and Photos, even Safari.

Sorry to start a thread over this but am I missing something?
I tried to Google it, but no use. Maybe I have bad Googling skills

 

[boast]

So Apple has Printer Pro as their free app of the week and I also downloaded HP All-In-One printing app but I don't know why should I use them?

Most if not all apps on iOS has a "print" option built in them like Dropbox and Photos, even Safari.

Sorry to start a thread over this but am I missing something?
I tried to Google it, but no use. Maybe I have bad Googling skills

Built in print only works with AirPrint certified printers.

 

[KTK1990]

Some connect with computer apps to turn the computer into a working print server that the app can connect to.

Good if you don't have an AirPrint compatible printer.

 

[Jessica Lares]

Printer Pro has options that the built-in one doesn't have. You can send photos to it, and print as a PDF, then go in and change settings like how many to put on a page, portrait or landscape, auto rotate, paper size, original size/fit to page/fill, and then pull that in an e-mail or wherever.

The HP app probably has similar options. I see that you can even control the scanner with it too. That is pretty sweet.

Sometimes you don't necessarily have the computer in front of you to do those things.

And sometimes you want to figure out what and how you're going to print something before getting to the printer.

 

[KTK1990]

As Jessica Lares said that it may have more features and allow you to fully use the printer.

With my Cannon printer all I can do is print. I can't select grayscale printing or anything. just print.