The very useful Teehan+Lax IOS8 Sketch 3 Templates have been updated http://www.teehanlax.com/tools/iphone-sketch-app 2013 Tools for the iPad (including PSD) http://www.teehanlax.com/tools/ipad
Teehan+Lax Pixel Density Converter
Teehan+Lax have created a pixel density online calculator that tells you how to scale graphics between 4 density groups. It is useful when creating applications across different platforms & devices. …