While Metro-styled apps are advertised as being full-screen experiences only, they can also support a less-well-known snapped mode, in which they can be used side-by-side onscreen with a second Metro-styled app or the Windows desktop. This Windows 8 feature, not coincidentally, is called Snap, and it’s named after a similar desktop feature that debuted in Windows 7.

Snap seeks to address what could be a major issue with Metro-style apps, in that while full screen experiences can indeed be immersive, they can also be quite limiting on large PC screens. But Snap isn’t particularly powerful: It only provides for two apps on screen at once, and one of those two apps is generally pretty limited. While Microsoft does requires app developers to support the snapped mode in even minimal ways, some apps currently offer next to useless snap experiences.

Snap isn’t particularly customizable either. You can arrange the screen in only two ways, with the snapped app occupying a thin sliver of onscreen real estate on the left or ride side of the screen. And you can’t arbitrarily resize this snapped area at all.

In this example, a snapped app is seen on the left side of the screen:

snap_left

And here, you can see the same app snapped to the right:

snap_right

Note that the desktop works with Snap, as either the snapped app or in the more prominent area of the screen. In snapped mode, the desktop provides thumbnails for each running application:

desktop_snapped

Snap can be enabled in a variety of ways, but it requires a bit of preparation. Generally speaking, you need to make sure that the app you’ll be snapping is running in the background and that the app that will occupy the larger part of the screen is currently running in the foreground. Then, you can use one of the following methods to snap the other app:

Mouse. Move the mouse cursor to the upper-left corner of the screen to display the Back tip thumbnail. Then, move the mouse cursor down the left edge of the screen to display Switcher. Select the app you’d like to snap from the Switcher list and drag its thumbnail to the right. The thumbnail will turn into a larger, floating thumbnail, and the side-by-side Snap bar will appear.

snapping

To snap the app to the left side of the screen, simply release the mouse button. To snap it to the right, drag the thumbnail to the right side of the screen and release it when the side-by-side Snap bar appears on that side of the screen.

Touch. Swipe in from the left edge of the screen. As you do so, the previous app in the back stack will appear as a thumbnail image under your finger. When that happens, swipe slightly back to the left to enable Switcher. Then, select the app you’d like to snap from the Switcher list and drag its thumbnail to the right. The thumbnail will turn into a larger, floating thumbnail, and the side-by-side Snap bar will appear.

To snap the app to the left side of the screen, simply release the thumbnail (by raising your finger off the screen). To snap it to the right, drag the thumbnail to the right side of the screen and release it when the side-by-side Snap bar appears on that side of the screen.

Note: There’s no keyboard-based method for snapping an app. But there are keyboard shortcuts for modifying the presentation of side-by-side apps.  You can use WINKEY + J to swap the snapped and primary apps onscreen. (Or via touch or mouse, simply drag the Snap bar toward the other side of the screen, letting go before you hit the screen edge.) If a snapped app is snapped on the left edge of the screen, tap WINKEY + SHIFT + . (period) to close the snapped app. Otherwise, tap WINKEY + . (period).

You can close a snapped app via mouse or touch by dragging the Snap bar to the closest screen edge. Or, just double-click the Snap bar.

You’ll find that most Metro-style apps aren’t particularly useful in snapped mode, at least in the Consumer Preview. But this is an interesting and potentially differentiating feature that could prove quite valuable as app developers become more familiar with the nuances of WinRT and Metro-styled app development.