As of now, I love the highlighting tool. I love how you can highlight in straight lines and how the highlighter automatically appears behind your writing or text, and doesn’t alter it’s colour.
However, on all the pictures you post on your website etc, all the hand drawn diagrams are beautifully coloured in.
THIS IS NOT REALISTIC.
To get a uniform line, you cannot lift your pen off your screen, otherwise the highlighter’s colour « builds up » to become darker.
This is very annoying because it makes coloring in simple shapes very difficult.
If you go outside the lines, you have to start all over again, and when you are coloring large surfaces, it confuses the software and bugs.
The line stops and « builds up » so you have to start again.
I am aware that the shape tool automatically colours in whatever shape you draw, but it doesn’t cope well with organic shapes like the ones you show in drawings of organs, for example.
Using a pen to colour in isn’t a great option either, because you lose the advantage of it being behind text, and being slightly transparent, which I think is a great feature.

I know this may not seem like a big priority, but I use this tool every five minutes, and wish it were better every time.

Small detail, but it would be a HUGE improvement :)