Designed to help teachers mark work you can use this add-on to easily add annotations and images to Google Docs & Google Slides which you can then move around easily. 

The main purpose of the tools is to allow you to use a Canvas to draw an annotate which you can quickly insert into your Document/Slideshow. The canvas allows for annotation with the mouse or touch screen and provides editing options such as colour and pen size. 

You also have access to some very fast buttons for inserting Green Ticks or Red Crosses to also aid in marking students work. Another feature is the 'Pop-Out' window which means you can insert much larger drawings or annotations very quickly.