This was a comment for the last thread and school closure.
For secondary schools (not requiring parents to be off) I think the majority of lessons might be done on the Messenger app from home.
This may work in part in first schools too.
It may at last give parents the option of keeping children off without worrying about essential education (GCSEs Alevels)
The teacher sets up a group chat for his/her whole class.
Pupils get notification to join.
They teacher sets up a video and points his camera to a white board (the teacher will need a surface you can write on at home)
The children can hear him but they see the board.
Facebook. The feature is available now on both Android and iOS. Group video chat on Messenger allows you to see up to six people at a time, but up to 50 people can join a call. Once more than six people are on a call, the main person talking is shown on-screen to everyone.21 Feb 2018
I use this as feature and having gone through many others, I can say this works. It's easy, although it might take a practice session to make sure the children can see the board.