To edit content you must click on the “wrench + screwdriver” symbol first to enter editing mode. You have to do this every time you want to enter edit mode (e.g. if you were before in pen mode). The first time you have to log in unless your credentials were stored by “remember me”. Only then will the tools above the red bar appear.
These tools enable you to add
The plus/minus sign permit you to add a new collection (before the present collection) or to delete the present collection (with all of its content)