Macbook Pro retina 13" Accessories

Just wondering what you guys think are some fairly essential accessories/apps for a first time macbook pro user, currently using the most recent 13" retina model and using it in school for programming/developing/coding. So far I've obviously used Xcode for coding, sublime text (however the license is a bit expensive) and sKedit for HTML coding.. I was wondering if anyone is in a similar situation.

Looking for a case recommendation, already got a bag/sleeve, and possibly wondering if anyone has used the PNY storEDGE before, is it any good?