Yes iphone apps run on ipad, but do they run in ipad native mode ?

[Combat squirrel]

As title really, I have 'outdoors GB' for my iphone, and it says on apples site that it works on the phone and ipad, now, if I got an ipad, would it install on that and run in ipad mode or just run in iphone mode ?

OR do I have to rebuy it again for ipad? (I hope not),

main reason is I want to use an ipad 3g as a mapping device when I go walks around snowdon.

 

[Combat squirrel]

Hi iphone apps work on the ipad they just run at the same size as the iphone screen but there is a touch button on the bottom right of the screen that says x2 witch stretches the app picture to the full size of the ipad screen

Edit: The apps that are solely for the ipad just run in full screen hd mode

Well yeah thats what I mean by iphone mode, I want to know that apps made for both.......can I install the ipad native version, because outdoors GB is expensive. - or can I download the maps iv used on my iphone for example without having to pay again even if I have to pay for the app ?