Mac OS X allows you to take a screenshot without interrupting your workflow. There is also some area flexibility when taking a screenshot.
Mac OS X or, as it is commonly referred to, OSX is the operating system that ships with all Apple Mac computers. It is comparable to Microsoft's Windows or a Linux system.
Certain app localizers (inc. Applingua) allow you to send entire app builds in order to see the inner workings of an app and to make sure all text, images and supporting html files are discovered and translated. In the case of OS X apps, it also allows localizers to translate and test on the fly.