Avatron makes the same Air Display available for Android on the Google's Play Store. I was looking for something similar to my iOS and I hit jackpot. The desktop client is the same and the app works and feels like the iOS counterpart. The client app works on both Windows and Mac OSX. Below are screenshots of it running in Mac OSX.
Set up is the same as before. You select your device (s) and adjust your secondary display arrangement.
The Air Display Galaxy Tab 2 is the bottom one of the right. I love running multi monitor displays on my macbook!
And voila. Wi-Fi palette monitor; using the Galaxy Tab 2 as a secondary portable monitor. You can use the touch-screen as a virtual mouse as well.
And here it is on a 4.65" Galaxy Nexus. As you can see, the soft keys take up quite a bit of space. A 4.65" screen is cutting it close to be useable.
A few things to note. With Ice-Cream Sandwich, you don't get the full screen. The virtual soft keys (home/back/menu) and task bar still exists. Hence, you lose some resolution compared to an iOS device.
1024x600 on the Galaxy Nexus
1024x540 on the Galaxy Tab 2
2048x1536 on the iPad 3 in Retina mode. (1024x768 other mode).
The only missing feature from the iOS version is virtual keyboard. Both have virtual mouses but with the iPad, you can pull up the tablet's keyboard to enter text or type within apps inside your Air Display monitor.
Next, the other issue is the inability to power multiple "Air Display" devices; meaning I am unable to use all my devices as 4th or 5th monitors at the same time.
I have some DisplayLink usb powered monitors and I can daisy chain up to 6 DisplayLink monitors to my MacBookPro. It would be nice to have a similar feature with Air Display.
Lastly, the refresh is rather laggy and slow. This is expected since the redraw is taking place over WIFI. The speed of your refresh depends on the speed of your WIFi network and your devices. Both my Samsung devices, in general, have poor WIFI connections. This doesn't bother me because I use these monitors as palette displays to show non-motion material. I use them mostly for displaying error logs, mail, and terminal windows which do not need fast refresh. Depending on your use case, this may not be ideal for you. Considering that the application cost $5, the investment is low compared to buying and lugging extra monitors around.
And a word of advice. If you ever plan to use a WIFI monitor or even some sort of Remote Desktop (VNC/RDP/X11), always choose a solid color like dark grey for your background. It makes it easier on the refresh and redrawing.
Link: Air Display at Google's Play Store