Apple has announced that applications designed for the iPhone 4 using its new iOS 4 will be able to fill the screen of an iPad.
The company has also announced that applications using the new operating system that are designed for the iPad will automatically adjust to work with the new Retina Display of the iPhone 4.
The iPhone 4's Retina display has a pixel density of 326 pixels per inch, the highest of any smartphone device, effectively quadrupling the resolution of its predecessors.
Apple CEO Steve jobs told delegates at the World Wide Developers Conference (WWDC) that Apple's new iOS 4 operating system would be able to automatically optimise existing iPhone applications for display on the iPhone 4, enabling them to take advantage of its higher resolution for sharper rendition on screen.
The new iOS 4 also provides full VGA output from the iPad, capable of providing 1024x768 resolution, allowing developers to add video output options to their applications.