Just want a bigger display for my phone. I need to know how I can EXTEND my phone's screen to another phone, by using bluetooth or wifi or RF or web? Few apps (idisplay, AirScreen, AirDuet screen, etc) exist for only mirroring/sharing the screen - but not extend it. Its like using two monitors for your pc side-by-side & you select 'Extend display' between two monitors and hence the display bisects into two monitors. Same principle for phones.
I haven't tried it (yet), but this might help, if you have the "dongle": http://www.displaylink.com/downloads/android.
There is also this: https://play.google.com/store/apps/details?id=com.andromium.os. But again, I haven't tried it.