I must admit that I was surprised that some of the apps that I was using for my trusty iPod touch (or an iPhone) have a "special" version for the iPad. Some, like FamView, which I purchased sometime back for reading my GEDCOM, automatically were "optimized" for the iPad.
So, you can tell when an app is for the iPad when it is listed at iTunes in the iPad section and when downloaded to your iPad it fills the screen automatically. Apps not optimized for the iPad are shown at 1x size with a screen that is the size of the iPod touch. To get them to fill the screen, you tap on the 2x found in the lower right corner.
Non-optimized apps are blurry to read when blown up but they are easier to see than the size of the iPod touch or iPhone. Some of mine had to be deleted before I could add the new version that is specifically for the iPad.
I will be reporting on the ones that I think are useful. BTW, the screenshots made with the iPad are much larger that expected. Don't make too many of them at once and share with friends or you will exceed their email-inbox mailbox limitations.