One or two panes

The same application displays as a split view application with two panes on some devices, yet displays as a single pane on other devices. What controls this?

With split views, you open two windows, assigning one to the left pane and one to the right pane of the split view. Not all mobile devices, however, can display multiple panes on the same screen. While the application code is the same, the mobile client displays either one pane (typical for phones) or two panes (typical for tablets).

If the device only allows a single pane to display, the window in the left pane is the first window displayed.

The rules for single-pane or two-pane display differ according to the mobile platform: