CategorySelect allows you to quickly add categories to a page without having to hit edit.
How to use it
At the bottom of the page where categories are listed, you are presented with the ability to add a category without hitting the edit button.
Click on the "Add category" button.
You will be presented with your cursor where you can start typing in a category name.
You can use an already established category or create a new one there.
Once you are done, hit save and the category will appear.
To delete or edit existing categories you must go into full edit mode.
There are a couple of advanced functions available:
Sort parameters - by clicking the edit icon next to the category names, you can define a 'sortkey' for that category. This sortkey defines at what point the article appears in a category page's listings.
If you would prefer not to use CategorySelect, you can disable it by going to your personal preferences, clicking on the Editing tab, checking the box next to "Disable Category module" and then saving your preferences.