This past March, Google introduced a new app store for its Docs and Sheets service inside of Google Drive. The marketplace offers various add-ons from the company's developer partners that bring even more functionality to the service. Here's how you can start adding new features to your documents and spreadsheets inside of Google Drive.
To download an add-on, open the "Add-ons" tab on the top menu bar and select "Get add-ons." A pop-up window will open with a variety of add-ons to choose from. Find the one you would like to install and click on the "Free" button to download it.
A second window will appear on the screen with information regarding the add-on's access to your data. It's similar to the permissions displayed when you are installing an Android app, simply click Accept and the add-on will be available to you immediately in your document or spreadsheet.
To open an add-on, click on the "Add-ons" tab in the menu bar, hover over the specific add-on you would like to launch, and then select the first option, which will say something like "Start" or "Show in sidebar." The add-on will then appear on the right-hand side of your screen; however, only one add-on can be displayed at a single time.
To remove an add-on, once again click on the "Add-ons" tab in the menu bar. A separate window will open which lists all of the add-ons you have installed. Click on the "Manage" button of the one you would like to uninstall and select Remove. From this menu you can also report any issues you find or even share your favorite add-ons with your friends.