Ksnip is a Qt-based screenshot tool that includes several useful annotation features for your screenshots.

ksnip is a small, cross-platform tool not only capable of taking screenshots but also allowing you to enhance them with its included annotation features. Easily capture screenshots through four simple options. You can manually designate a rectangular area, capture the full-screen area/current monitor only, and the active window.

ksnip works in the same manner as most screenshot tools, but the added annotation options set it apart. The interface is easy-to-navigate and provides access to all you need to make a quality screenshot image. There is a toolbar with the available capture modes, there is also capture delay mode, along with toolbar located on the left-hand side. ksnip will be useful for everything from presentations to meme-making and anything in-between.

Ksnip Features:

Take a screenshot of a custom rectangular area that can be drawn with a mouse cursor
Take a screenshot of the screen/monitor where the mouse cursor is currently located
Take a screenshot of the full screen, including all screens/monitors
Take a screenshot of a window that currently has focus
Take a screenshot of a window under the mouse cursor
Take a screenshot with or without the mouse cursor
Customizable capture delay for all capture options
Upload screenshots directly to imgur.com in anonymous or user mode
Command line support, for taking a screenshot and saving it to a default location, filename, and format
Customizable default location, filename, and format for saving new screenshots with wildcards for Year ($Y), Month ($M), Day ($D) and Time ($T)
Print screenshot or save is to pdf/ps
Annotate screenshots with a pen, marker, rectangles, ellipses, texts, and other tools
Many configuration options