It's quite simple really. If you've got a Windows 8 Phone you need to get App Folders. It lets you organize your applications into, er, folders, making them much easier to navigate. I've got tons of apps on my phone and scrolling through the list gets quite tedious. Of course, I can pin the important ones to the start screen, but then that gets kind of large too.
App Folders lets you create a folder that contains a subset of your apps. You can then pin this to the start screen, giving you quick access to those apps. You can see it in action above, where I've put all my photo processing apps in one place.
When I tap the folder on the start screen I get instant access to all the apps in it. You can create as many folders as you like, and really get yourself organised. You can find the program (it's free by the way) here.