Made by Evernote, the Skitch App allows users to annotate their pictures using a wide variety of options. This app is especially useful for those working with screenshots. The Skitch app, however, is not for image manipulation or editing; users can just write and draw on them.
For example, users may want to place arrows on the picture or write some text on it. They can also zoom images to do some detailed work, or can go to a selection tool to change the size of annotation or its colour. It is a simple app which works very quickly and this is precisely what makes it popular. Skitch also allows users to crop images so they can work on certain details. 
Skitch works very well with Evernote and if the app is being used on tablet, it is so much more fun. Skitch allows users to share their creations as easily as other social apps, so users can send their images either through Facebook, Twitter or even Gmail. Skitch is available free for download on Android Market.