How to use your iPad as an external monitor over Wi-Fi

The iPad display is capable of so much more than firing pin-sharp pixels at your face. They say there's an app for anything, and while many throw a spanner in your productivity gears like Twitter or Facebook, some can improve your workflow in unexpected ways -- such as rigging up your iPad as an external display over Wi-Fi.

A second monitor could sit next to your laptop as a simple widescreen mobile hub, or alongside your desktop computer as extra visual land to keep those heavyweight widgets off your main screen.

It's not just available for Macs either. We'll be using Air Display (£6.99 on the App Store), which can pair Macs or PCs with an iPad, iPhone, Android device or even other Macs, should you lack the necessary ports.

There are cheaper apps that can do a similar job, like iDisplay (£2.99), or DisplayPad (£1.99). After weighing up customer reviews, it looks like Air Display is the safest bet, so grab it from the App Store and start preparing your Mac with this guide while it downloads.

Preparing your Mac

• Download the Air Display software, which connects to your iPad over Wi-Fi.
• Pick the combination of hardware you'll be using. This guide will use the Mac to iPad/iPhone software, but whichever way you swing, click the big blue 'download' button. It should download automatically, but if not, you'll be given a direct link to nudge it along.
• Once downloaded, run the installer as you would with any other desktop app. It'll ask you to restart the computer, so go ahead.
• Your rebooted desktop should now include this icon in the menu bar:

Connecting your iPad

• Grab your iPad, make sure it's connected to the same Wi-Fi network as your Mac, then load the Air Display app.
• Return to your Mac and click the menu bar icon. Check that Air Display is turned on, select your iPad in the drop-down menu.
• If your iPad isn't in the menu, look on the Air Display iPad app, which offers a direct IP address. Back on the Mac's drop-down menu, click 'Connect To Other' and type the IP address.

Check the settings

• You're connected but there's a little more tweaking to do yet. Go to System Preferences, where we'll be setting the Air Display and Displays preferences.
• We'll check the new Air Display settings first. The default new iPad retina resolution can make elements far too small on the screen to be usable. One day, all Mac apps will be designed with HD in mind, but in the meantime, we'll switch off 'Use Retina resolutions when available'. You might want to tick 'Auto-check for updates' while you're here.
• Now to the Display preferences. Place your iPad next to your monitor (or wherever you plan to use it), then click the 'Arrangement' tab. The smaller blue box represents your iPad and the white bar dictates where your OS X menu bar will sit.
• Check the menu bar is on the bigger display, then position the smaller blue box in the same place that your physical iPad is sitting. Don't worry if the screens flash blue while you make these changes, it's perfectly normal.

Now you're set! Air Display runs pretty smoothly but you might experience a little lag, depending on the speed of your Wi-Fi router.

There's a known issue with MacBook Pros from 2008/2009, but it's not a deal-breaker. The app developer recommends simply putting your Mac to sleep then waking it whenever you login on restart.

How might you use your freshly mown screen space? It could be a good home for your Twitter and Skype chats or a permanent email window. Let me know what you think in the comments or on Facebook. Perhaps at the same time -- from both screens.