So up here in Canada, there was a webinar pertaining to online labs (hosted by STLHE).  They divided participants into different groups based on their interests.  Here is the link to the google doc they created.  Some useful tidbits:

https://docs.google.com/document/d/1p2JZATEG8A7QzIJ2aWrRbHuKGQjaP1zG71C5v60e_78/edit#

Anyway, they mention a software called OPENBOARD.   Has anyone tried this?  

From the link above:

"Closed captioning - one problem just for voices, but what about when drawing on the screen, whiteboard, etc. - deciphering handwriting? 

• There are tools that work well for Math that can work for sciences as well (especially if the instructor has an iPad or some kind of tablet). (One of our faculty loves OpenBoard https://openboard.ch/index.en.html for Zoom lecture and async video creation) 
• OpenBoard, the best interactive whiteboard for schools and universities

Please feel free to comment on this and if you have any other software suggestions in this same vein, that would be great.