Wikipedia
Monosnap
Monosnap is a free screenshot program for Mac OS X and Windows. The program allows users to create screenshots, annotate them and upload them to the cloud. It was released for OS X on 11 July 2012. Several days after it was positively reviewed by sites like Addictive Tips, freetech4teachers, OneDayOneApp and MakeUseOf, an update was released on 5 August 2012, providing authorization with email. On 10 August there was a release for Windows, providing similar functionality.
Since 9 October 2012 (version 1.4.0) app allows to upload images to FTP, SFTP or WebDAV Servers. Right now it also has in-app turning on external services support (Dropbox, Evernote, Box.com, CloudApp).