Opacity is a really great vector editor for Mac and I frequently use it for iOS icon design because it has a lot of features useful for development (for example, in Hipster Lab I used it to create Quartz drawing code for all the facial elements, removing the need for large varying-resolution PNG files). However, I only had the iOS 7 icon grid as an SVG file, so I set the grid up in Opacity and put it on GitHub.

The Opacity file can setup as a template (File > Save as new template) and it contains a layer for the template itself as well as layers for all the gradients and colours on ios7colors.com.