Snippy is a very lightweight program to take screenshots and send them to the clipboard. But, it really stands out due to one specific feature, and that's that the captured zone will be the zone we specify by drawing on the screen with a virtual marker.
It's very easy to use, all you have to do is press F11 (or the key you have previously configured) and specify the area of the screen you want captured. This selection will be stored on the clipboard, so you can later edit it with a text application or a drawing application. You also have the possibility to directly save it as a file with one of the following image formats: BMP, JPEG, GIF, TIFF or PNG.
From the application's Settings menu, that appears by right clicking the scissors icon that appears in the notification area, you can configure other options like the thickness or color of the marker.