The iPad can run iPhone apps in compatibility mode, and we all know Apple implemented this feature to allow iPad owners to access a huge catalogue of apps on day one. The fact that the iPad App Store got to more than 40,000 apps in a few months is a different story. What is not great about iPhone compatibility mode is that, when an iPhone app is blown up to 2x mode, the graphics become fuzzy. Even if you've installed on your iPad an app that's got Retina Display-ready graphics on the iPhone, you'll get the pixelated graphics.
RetinaPad, a new Cydia tweak by Ryan Petrich, fixes this problem, and it works great with basically any app or game that's got Retina graphics. Once installed, you'll have to choose the iPhone apps that you'd like to run with the new 2x mode. Fire up the app, tap on 2x and you'll notice that the iPad will display clean graphics without pixelation. If the iPhone app has been updated for the Retina Display, it most likely works with RetinaPad out of the box. It's really neat.
I've been able to successfully run in the 2x mode Spotify, Voices 2, Calvetica -- they all look great on the iPad now. RetinaPad is available at $2.99 in the Cydia Store. More screenshots below.