In the clearest indication yet that a new model is on the way, the rumoured iPad Pro is likely to have a screen resolution of 2732 x 2048, much larger than any previous Apple tablet.

Developers digging around in the beta of iOS 9, Apple's upcoming operating system for the iPhone and iPad, found references to the resolution, which was also predicted. Assuming rumours of a 12.9-inch screen are correct, then the iPad Pro will have a pixel density of 263 per inch, just one less than the iPad Air 2.

A larger iPad has been rumoured for several months now, but nothing has yet leaked out of Apple's supply chain, suggesting that if there is one in development then it hasn't yet reached mass production. An autumn release date is expected - to coincide with the public release of iOS 9 and new iPhones - so this will remain the case for several weeks yet.

The new resolution, reported by 9to5Mac, means developers will have an easy time scaling up their apps to fit - although of course it's likely many will redesign them to take advantage of the extra space, just as iPhone app creators did when the first iPad arrived.

Adding fuel to the flames are changes Apple has made to the iPad's keyboard in iOS 9, and how multitasking with two apps on the screen at once is now possible - a key benefit of having a larger screen.

With the extra space and functionality offered by a larger iPad, Apple will likely aim its new tablet at the 'prosumer' market of customers who want more advanced features and the ability to use their iPad for work tasks as well as pleasure. The business and education markets are likely to be targeted by Apple for the launch of the iPad Pro.

As well as a larger screen, the iPad Pro is expected to stand out from the rest of the range by getting its own stylus and extra ports, possibly including USB-C.