It is very handy, as opposed to opening another website to copy and paste an emoji from, however the emoji selection is limited to the first 106 (yellow faces through angry cat). Thank you for being the only one to provide as an add-on to Google Docs, but until there are more emojis, I will be using a Chrome Extension instead. I'll check back in the future and if you offer the full set of emojis (e.g. what is on an iPhone), you will definitely get a 5-star rating.
For anyone only really wanting the yellow smiley faces, this is already fantastic & you should install it! 😊