Since the latest Firefox update a new iconis available in the browser's toolbar: Pocket
Using Pocket you can remember web pages and read them later. Pocket is useful because you can use this application from any device. So you save a webpage within Pocket on a desktop PC, sothen this could be read on the go on your tablet or smartphone.
Who would not want to use this feature and remove the Pocket icon from the menu bar of Firefox, can do so as follows:
Click with the right mouse button on the Pocket icon on the toolbar. A window will open. Selects now "Remove from toolbar". Finished!
Immediately you will not find the icon of "Pocket"in the Firefox toolbar.