[sphericalgames]

> All existing apps will be rendered into the current 320x568 frame buffer and scaled up. It's really no different to an iPhone app running on an iPad in that respect.

I don't think it quite works that way. In the past, your iPhone app was designed to run on iPhone only and it upscaled if you attempt to run it on iPad and the OS knew it had to do this due to a checkbox setting in xCode.

Nowadays, most apps are universal and runs on any device by adjust the output according to device resolution and given scale factor. Basically the scaling is handle internally by the program and not by the OS as described above. In theory, your app should be future proof if you did this correctly.

That said, you need HD Retina graphics so that your code avoids upscaling images. Beyond that, everything else such as fonts are not upscaled but drawn to scale.