Depends. All iPhone apps are compatible in iPad. However you will be using a scaled down version.
If you brought a universal app than you won't have to pay for iPad version.
Angry birds has a seperate iPad version you will have to pay to get "HD" graphics.
This is my biggest complaint so far about the iPad. There should be a way that iTunes should see that you already purchased the app on your phone and then offer you some type of "iPad upgrade fee" for a few dollars or so. I know that's up to the developers and Apple but it's definitely something they should look into. I really want Real Racing 2 on my iPad2 but I already have it on my iPhone 4 and I can't really see spending another $10 on something I already have and completed just for a bigger screen.
I really want Real Racing 2 on my iPad2 but I already have it on my iPhone 4 and I can't really see spending another $10 on something I already have and completed just for a bigger screen.
Download the app AppShopper and add Real Racing to your "want list". When they have one of their inevitable one- or two-day sales, AppShopper will push out a notification so you won't miss it. I've gotten a lot of apps at far better prices (and sometimes free) that way.
On the iPad it's pretty easy to figure out, if you already bought something it will say install in the app store rather than having a price next to it.