What is the difference between iPhone and iPad apps?

[Denis54]

I just bought an iPad and will get an iPhone in July.

When I look at the App Store I see that an application has different versions whether it is to be used on an iPad or an iPhone.

For instance, GoodReader has a different app for the iPhone and the iPad.

If I buy the iPad app, will I be able to install it on my iPhone when I get it in July or will I have to pay again to install it on my iPhone?

Out of curiosity, could you tell me if it is possible to use an iPhone app on an iPod Touch?

 

[wizee]

Just look at the requirements on the left under the price, or look for the + mark, that tells you that it will work for both. I don't know about ipod.

 

[benhollberg]

If there is a little + sign on the price it is universal and works for iPad, iPhone, and iPod touch. If no + sign then look at the screenshots to see which device it works for. When on an iPhone or iPod touch you can only find iPhone and iPod touch apps. When on an iPad you can find all apps.