Contrarily to the other mentioned before, it is opensource [1], and you can easily host your own instance if you don't like the idea of sharing your whiteboards on a random server on the internet.
Drawbacks I saw (for my own use patterns):
- Not great for use with a pencil-based tablet: pencil vs. hand or other pointer are not distinguished. I don't want my finger to draw, I want only my pencil to draw.
- Couldn't find how to permanently set a different size for pencil vs. eraser. I want a huge eraser (and a large eraser didn't work too well, independently of this comment) but a thin point pencil.
- No "erase region" or "clear page" functionality.
All of the above may look independent, but in fact are highly inter-related. If I wasn't constantly smudging the screen with my fingers being confused for pencils, I wouldn't need an eraser that much. If the large eraser worked well (and I didn't need to reset the size every time I switch from pencil to eraser) I wouldn't need the "clear board" functionality.
If you already have an undo system then you could push the pre-cleared state to it as well.
it's easy to make armchair feature request suggestions when I haven't even so much just looked at the code, so I will end by saying good work on having a tool that people actually use!
Good show!
It's impossible to get something exactly like Apple Pencil/iPad Pro, in a shared Web-based tool, but this comes close.
Edit: it's quite a bit better in chrome, but still not perfect.
Works very well with the pen indeed. I love this, and the fact that it's self-hostable only makes it better. Also, props for deferring to the system color picker!