The right resolution for App Design ? (iPhone App.)
So I need a bit of help with an app design.
It's my first one, it's just to test out my skills..but I can't seem to get it right.
As far as I know the resolution of the iPhone 4S is 640x960.

Everybody says something else, the DPI should be higher than 72.. (163 or even 326)- I do not understand why.
Couldn't find an article about this..
So my questions are:
What is the right resolution ?
What is the right DPI setting ?
What else should I know ?
All of this in order to make a high-quality application.

Thanks in advance. 
(I hope I'll get an answer from an experienced designer.)

The right resolution for App Design ? (iPhone App.)
===

So I need a bit of help with an app design.
It's my first one, it's just to test out my skills..but I can't seem to get it right.
As far as I know the resolution of the iPhone 4S is 640x960.

Everybody says something else, the DPI should be higher than 72.. (163 or even 326)- I do not understand why.
Couldn't find an article about this..
So my questions are:
What is the right resolution ?
What is the right DPI setting ?
What else should I know ?
All of this in order to make a high-quality application.

Thanks in advance. 
(I hope I'll get an answer from an experienced designer.)
