Duet Display Pro could be your new favourite creative app. Created for the iPad Pro, it lets you use your tablet as an additional screen to your Mac or Windows PC – and draw using the Apple Pencil in the likes of Photoshop, Illustrator and Painter. 

Duet Display has been out since the beginning of 2015, but that 'standard' version merely lets you use an iPad as an additional (touch)screen for your PC or Mac. That's perhaps useful for the travelling creator who wants to add an additional screen to their laptop – but it's with the new Pro version that it comes into its own. Duet Display costs £7.99/US$9.99 from the iTunes App Store. Upgrading to the Pro version is an $20-a-year in-app subscription (that's around £16.50 currently, blame Brexit).

To use Duet Display Pro, you install apps on both your iPad from the iTunes App Store, and the free companion app for Mac or Windows from duetdisplay.com. Launch the iPad app, connect the USB-to-Lightning cable between the two, and your iPad becomes an additional screen on your desk.

Pull your design or art application onto this screen – whether Photoshop, Illustrator, SketchBook Pro or Manga Studio – and you can draw on it using the Apple Pencil. There's full support for pressure and tilt, and drawing this way is rather lovely. Getting your apps to fit into this second screen properly was sometimes fiddly – but once it was set, everything became super-easy again. I've been testing Duet Display Pro for a few weeks now – including the beta version – and I've yet to see it work anything less than reliably.

Control over this additional screen is via an icon that sits in your Mac's Menu Bar or the system tray in Windows. This lets change the resolution, frame rate and display quality of what's on your iPad. Most of these are to allow you dial-down the quality to save the drain on your laptop battery, so you may never touch them. The one you'll want to try multiple versions of is the resolution, between Retina and High Resolution. Both give you the full 2,732 x 2,048 resolution of your 12.9-inch iPad Pro (or the 2,048 x 1,536 res of the 9.7-inch model), but the Retina mode means Photoshop get a nicer looking interface that also larger. This take up more of your iPad Pro's screen – which makes buttons easier to hit but reduces the size for your artwork, graphics or designs. Which works best is a personal decision.

iPad Pro vs Cintiq 13HD

So how does an iPad Pro with Duet Display Pro stack up against Wacom's Cintiq 13HD tablet display (below)– or its new MobileStudioPro?

The Cintiq is easier to use. The buttons and control wheel make using Photoshop and Illustrator easier – as you don't have to touch your keyboard for simple modifiers or to bring up brush parameters. Photoshop understands the Cintiq more – which could be down to Wacom's drivers – you never seem to need manually tell a brush to respect pressure or tilt, as we often did with iPad Pro/Duet Display Pro.

There's also an inherent difference in their stylii. The Wacom Pen is bulkier and has multiple buttons, while the Pencil is light and simple. Saying which is better is like trying to decide between a Rotring pen and a Faber-Castell Pitt Monochrome Graphite pencil – only you know what's right for you.

If you already own an iPad Pro, choosing an iPad with Duet Display Pro over the Cintiq 13HD is a no-brainer – unless you have £600 to blow just for that more easy control. If not, the choice is trickier as an equivalent iPad Pro with enough storage to be worthwhile (eg 128GB) costs at least a couple of hundred pounds more. It all depends on how useful having a large tablet is to you.

iPad Pro vs MobileStudioPro

Another comparison for the iPad Pro with Duet Display Pro would be Wacom's new MobileStudio Pro – an upgrade to its Cintiq Companion. This is a full Windows 10 tablet that turns into a Cintiq if you plug it into a Mac or PC. It's a lot more expensive than the iPad Pro – Wacom's pricing starts at £1,399 – but you get something capable of running Photoshop, Illustrator et al in their own rights.

So in short, Duet Display is a must-have app for designers and illustrators who own an iPad Pro. Go buy it.