To support the Retina display you have to make two versions of every raster
image in your iOS apps. That can be a pain to keep everything in sync when you
have to make changes.
Opacity is an image editor that solves this problem by letting you set
up “factories” that export the same image in multiple resolutions. I’ve been
using it for the last year and a half and it’s been a marvelous timesaver. I’ve
built or imported all of my icons and raster pieces with it. Well worth the