New Google Drive add-ons, How to use them?

On March 11th Google presented for the first time add-ons for its Office apps. More specifically Docs and Sheets are the services which are getting this new feature. Basically the idea behind this is to do more without ever leaving the Drive. These add-ons are not written by Google itself, instead 3rd party developers are invited to create as many of them as possible.

Now, approximately one month later there are 35 add-ons available, from Charts to Bible Verses.
To find the add-ons all you need to do is to open a new document or spreadsheet. There on the menu bar you can find the "Add-ons" button.

Click it and then just find what you want to add. Being a student, I often have to write bibliographies for papers. They can be a pain. So for the purposes of this article I am installing the "EasyBib Bibliography Creator". After you press add, a permission window, like the one in Android, will pop up. Press Accept.

After installing to launch the Bibliography Creator all I need to do is go to Add-ons again and press Start or Manage the Bibliography in this case.

The add on will usually appear in the a sidebar to the right of the page. Keep in mind that only one add-on can be displayed at a time.
To remove an add on simply go to Add-ons>Manage add-ons... The click manage on the add on you want to remove and press Remove.

Enjoy these new features! Here is the video Google prepared for this new feature.