1. Go to Settings > Desktop + Mobile Apps, and click the Install Plugin button underneath Gmail.
2. You will be redirected to the Chrome App Store. Once you're there, click the +Free button on the top right.
3. In the pop-up dialog box that appears, click Add.
4. You will then notice the blue +Free button earlier turn to green but now says Added to Chrome.
5. Open or refresh your Gmail and you should see the Contactually extension on the right side of the screen, next to your settings.
5. Once installed, you will be able to bucket contacts right from your Gmail compose window. You can both add new contacts to your buckets or change contact's buckets if the relationship has changed. You can also add a tag and even tell the system to not add the contact. Once your message is sent, those contacts are automatically saved to your Contactually account.
You will also be able to see your follow up suggestions right in Gmail.