ScreenshotPlus is an interesting widget with which you can take screenshots of both the full screen (with and without a timer), the selection of the screen that we indicate, as well as the chosen desktop window and even any other widget. Captures can be saved to the clipboard or hard drive, or they can be exported to any application directly from the widget.
Once the capture is made, it offers the option of deleting and redoing it, or saving it in different formats (jpeg, tiff, jpg, pdf, gif) and opening it with the preview or importing it into iPhoto. It also allows you to preview the capture before saving it, passing a magnifying glass to see the image in more detail.
In the configuration options you can choose the folder in which you want your image to be saved by default, as well as the default name that you will give them. Once the capture is made, you can choose to save it, show it on the desktop, open with preview or save and open. You can also select the application with which you want it to open by default: preview, iPhoto, Safari, Firefox and even Photoshop if you have it installed.
In particular, it is a widget that I have been using for a long time both for its simplicity of use and for the convenience of being able to perform various types of captures with a simple click.
Download | ScreenshotPlus