iPhone, iPad Screen Sizes

This is old news for iOS folks, but I wanted to pull together a few things into one place.  I did not find anything like this in the first google search or two I did, and it was a worthwhile task to go research it myself in more detail.

In essence, there are only two screen sizes to mess with when doing iPhone/iPad development.  In the Android world, there are many many different screen sizes and resolutions.  There, I have solved a number of interesting but time-consuming puzzles with combinations of -ldpi/mdpi/hdpi drawables (and dimens) and small/normal/large layouts to make sure things look ok across the spectrum of possible devices.

As of iPhone 4.4S, Apple did have to introduce a new screen resolution for the phone, which resulted in them introducing the notion of an Android-like device-independent pixel called a "point".  The size of the phone's screen is 320x480 points no matter what.

So, here is the blissfully small list of possibilities:

Possible Screen Sizes for iPhone, Pad
Device	Screen Size in Points (Pixels)	Resolution
iPhone 3 and prior	320x480 (320x480)	163ppi
iPhone 4, 4S	320x480 (640x960)	326ppi
iPad	768x1024 (768x1024)	132ppi
iPad3	?768x1024? (1536x2048)	264ppi