With Nokia pushing its Lumia "Black" software update to all Windows Phone 8-based Lumia handset, it's time to start looking at some of the unique new features and apps this update provides. And the first is a surprise, a new app called App Folder that lets you collect multiple apps into a single group that can be accessed from a tile on your Start screen.

Remember, you can learn more about Nokia Lumia "Black" in The Complete Guide to Windows Phone 8 Update 3 and Lumia Black.

Suffice to say that Windows Phone users have asking for an OS feature like this since, oh, I don't know, there was a Windows Phone. This isn't that feature, and it's not integrated cleanly into the OS in a manner that will please purists. Instead, it's just an app. But it does do the job.

You can install App Folder from the Windows Phone Store. It requires a Nokia Lumia device running Windows Phone 8, presumably with Update 3 and Black, though I've not tested that to be sure yet. It appears in your app list as App Folder (and not Nokia App Folder, as per most other non-HERE Nokia apps).

The UI is simple enough: Tap the Add ("+") app bar button to create a new folder and then give it a name.

Then, using a screen that looks like the Apps list, select the apps and/or settings you wish to add to the folder.

When you're done, the folder is presented to you as a list. You can reorder the list so that the apps are in the order you prefer.

Or, tap the Pin app bar button to pin the folder to your Start screen. (I can't imagine why you'd create folders with this app otherwise.)

Pinned folders can be resized to any folder sizes Windows Phone supports, which is nice.

Unfortunately, the folders don't open in-place on the Start screen as do the native folders in Android and iOS. This is where the fact that this thing is an app, and not an OS feature, gets in the way. Instead, the folder just opens in the app itself, as a list.

So, not totally useless. But not as good as many would want.