App Switching in Windows 8

In Windows 8, it's possible to switch back to a previous app by swiping in from the left screen edge. Which previous app? That's not always clear. Bardi Golriz explains:

See, on Windows 8, the app that's swiped in from the left edge depends on when you last did a left swipe to switch apps. If like in my example you wait a second or more, you're returned to the previous app. The time delay results in an assumption made that you're continually switching between two specific apps. For example, you're writing an email but consulting a website/document/etc. as you write it. However, if you do a swipe within a second or so of the last, the switched to app is not the one you were on previously, but the next in the queue. The assumption here is because of the minimal time interval between swipes, your intention is to swipe through your running apps rather than jumping back to the last app.

This is pretty clever, but probably often results in showing an app the user did not expect. I think webOS and the Blackberry PlayBook solved this better, by spatially arranging running apps horizontally. This way, it's always clear which app you switch to when you edge-swipe,¹ because apps never "move"; the same apps are always located to the left and right of any given running app.

If you're not sure, just zoom out, and you'll see all of your running apps neatly arranged.

Addendum: Follow-up from Bardi Golriz.