I stumbled on this trick by accident, i could not get the dual screen to open any apps in windowed mode until i installed Sentio desktop on the phone, the app opens in landscape mode only and can display across both screens, if you add app shortcuts to the top of the screen and click on them, those apps will open in windowed mode on the dual screen. Sentio will crash in the background on the dual screen and goes to recent apps, but the windowed apps stay open on top.. works nicely if you want to multitask in landscape mode like using your main screen for the keyboard and pop back and forth between apps on the dual screen.
Our Apps
Get our official app!
The best way to access XDA on your phone
Nav Gestures
Add swipe gestures to any Android
One Handed Mode
Eases uses one hand with your phone