Before you just go download it, let me explain the thinking behind the grid.
The iPhone resolutions so far are:
640 ✕ 960 & 640 ✕ 1136
If you want to sub-divide those into the largest possible squares you need to find the highest common divisor. On the iPhone 4 that is 32px, on the iPhone 5 it’s 16px.
I recently heard that not many people know about this feature, even though it’s been around for about a year.
Photoshop didn’t use to render fonts very well for digital mediums, which use sub-pixel rendering to anti-alias fonts - making them appear slightly thicker but not as thick as the “Strong” settings.
As a result, if you wanted to mock-up a website or app, the font rendering options never quite matched the way fonts appear when loaded on a browser or mobile device.
Photoshop then added two new rendering options, Mac LCD and Mac, which solves the problem beautifully!
Today we released something called Asset Handoff that bridges the gap between design and development. We’re excited to show it to you.