656 votesMerg commented
I would like to chime in too. I just purchased squid because its so good, but I used One Note and one thing they did good on the full version of the surface was the ability to customize and place short cuts of whatever pencil or highlighter color in a couple of custom spaces.
It looked really pretty too. You would be able to create for example an orange highlighter and place it into one of the empty boxes up top and the icon would reflect as well. You'd see only the tip of the highlighter but you would know its a highlighter because of its angled edge and its color being orange. The same thing goes for a pencil or pen, you would be able to tell based on the tip of the tool in the icon and the color.