An easy to use app that's now also available for Windows 8 - Skitch. The benefit of this app is not that it's an editor for images. It isn't really that. Think of it as an instant way to comment and create from images very fast- as fast as your imagination can run. You've probably seen the results of it on social networks where unexpected or humorous comments accompany mundane or well known images. Popular images may be copyrighted so have some common sense. A good source with this tool is opened up with YouTube. You've probably seen various messages superimposed over Willie Wonka:
The screen grab and captioning take mere seconds and you're on your way to a high impact message.
More serious uses are innumerable and even using the tool to create infographics are not out of the question.
Promoting a community or real estate service takes on an added visual dimension in just seconds. The app does a little markup magic too, taking cues from the webpage the screenshot came from and applying a relevant name to the image file.
Vero Beach real estate shown in the above image promoted by Norris and Company, Vero Beach FL.