App: Clip It! for Safari
Developer: Owl Coffee Deer Ltd.
Genres: Utilities, Developer Tools

Take screenshot of onscreen element from Safari quickly and easily.

Enable this extension from Safari.

1. Control-click (right-click) on the HTML element on Safari. 
2. Choose "Capture Selected Element". 

The screenshots are saved in your “Downloads” folder

Release notes:
In the menu item, you can choose to disable/enable Clip It!. When you don't need to take screenshot, the detection highlight won't appear anymore!