If you’re like me, multiple screens are a great productivity enhancer. Android and iPad tablet owners can leverage their tablet screen as an additional monitor for their PC. REDFLY ScreenSlider by Celio ($1.99 USD) and iDisplay by Shape.ag ($4.99 USD) are two apps that can help maximize desktop display potential. ScreenSlider is an Android/Windows-only app, while iDisplay supports Android, Windows, iOS, and Mac.

Both apps redirect an additional desktop display to the LCD on your mobile device. You download and install the app on your mobile device, and then install a client that runs on your desktop. Both devices must be on the same network. Once installed, open the client on your desktop and connect to the app on your mobile device. You should see an extended desktop on your mobile display and be able to move windows from your desktop onto your mobile device.


Setup of iDisplay was straightforward on my Windows 7 laptop. After installing the app on my Android devices, I installed the client on the PC. A Windows Firewall exception request appeared. After allowing the exception and joining both devices to the same wireless network, I opened iDisplay on my device. The connection screen displayed the machine name of the laptop. Touching the laptop’s name initiated a connection. The screen flashed, and then I had an additional PC desktop on my mobile device screen (see Figure A).
Figure A

Windows 7 running on external iDisplay on Android TF300 (note the Android task bar at the bottom of screen).

Initially, the display was unsuitably small. In the settings menu, I set “Zoom” to “1x”. I had to disconnect, exit the app on my tablet, and reconnect to get the zoom settings to update. Once complete, the resolution was far more useful. At 1x zoom, you can still use pinch-to-zoom gestures to resize the external display.

Performance was a mixed bag. I had one disconnect between my desktop and the tablet, forcing me to reconnect. I also had some difficulty getting the Android tablet to see the Windows PC client software. Entering the client manually by IP Address and Port did not connect, but after failing, the client window refreshed, displaying the client PC name. Clicking on the PC name then connected. This process was repeatable, but not consistent.

Open windows on the tablet display switched back to my regular display when communication was lost. Interestingly, while Chrome performed well on the tablet display, IE 9 was a dog, becoming unresponsive and not refreshing. I was also able to move my Outlook client to the external display and found it crisp, readable and responsive (Figure B). Android screenshots of the Windows apps worked great. CNN video was choppy, but it worked.
Figure B

Outlook 2010 on external iDisplay on Android TF300 tablet.

The Windows client can be set to start automatically or loaded manually when the PC boots. You can also exit completely from the system tray. The client allows only two setting to be modified: the option to launch at startup and the external “Display Arrangement” location (left or right of the normal PC display). I was able to pair my Droid 4 alone and in a Lapdock with iDisplay, and with Mobile View stretched to full screen on the Lapdock, the additional desktop worked out nicely. It also worked well with my Transformer TF300 (Figure C) and on my Mac (Figure D).
Figure C

iDisplay native app on Android TF300 tablet.

Figure D

Mac OS X running on external iDisplay on Android TF300.

REDFLY ScreenSlider

ScreenSlider installed in the same way as iDisplay and requested the same Windows Firewall permissions. Unlike iDisplay, connection is established from the ScreenSlider app in the system tray on your PC. The more expensive “pro” version ($9.99 USD) allows you to initiate connection from the device to the PC. ScreenSlider does not have a “zoom” function, and it displays the screen in a default 1x resolution. Touchscreen gestures are also limited to the “pro” version. On the initial successful connection, a PIN displays on the external device that must be input on the client PC before the screen will be shared.

I did not experience any disconnects, but I had the same challenges pairing as I did with iDisplay. I was unable to ever successfully pair my Droid 4 to my Win7 laptop at work using ScreenSlider, but it worked on my home network and PC (Figure E). It also worked nicely with the Droid 4 in the Lapdock.
Figure E

Windows XP on external REDFLY ScreenSlider display on Android TF300 tablet (note the Android task bar at the bottom of the screen).

When disconnecting, any active apps on the external monitor returned to the laptop display. IE 9 performed even worse on ScreenSlider than iDisplay, refusing to refresh when clicking on links and remaining stuck on the homepage. Chrome, on the other hand, enjoyed improved performance on ScreenSlider. CNN video was smooth, with only a little audio/visual sync lag. ScreenSlider had an obvious performance edge. Outlook was quicker, and resizing and moving windows on the external display on the Droid and TF300 were both more responsive than with iDisplay.

The Windows client for ScreenSlider Settings can also be set to start automatically at boot or load manually, plus you can exit completely from the system tray. Similarly, you can select the location of the mobile device left or right of the PC in the settings.


Unfortunately, this is a case where neither product has a clear advantage. These apps offer the most utility to road warriors who carry a tablet and a laptop when they travel and want to have a convenient second display. Although ScreenSlider failed to reliably connect with my Droid 4, the advantage in snappy performance and consistently reliable connections with my TF300 tablet give it the slight advantage.

In contrast, iDisplay connected to both devices, but it consistently required me to enter IP addresses and rescan in order to see those devices in order to connect — and was noticeably slower. If you’re looking to hook up an Android tablet to a Windows PC, I’d recommend ScreenSlider. If you want the flexibility to share displays with Mac OS X and Windows PCs and don’t mind a little performance hit, iDisplay may be the better choice.