Does a simple remote classroom package exist?

My fiance is a high school teacher, her school does have the ability to administer tests online but they don't have a way to actually teach online. Covid-19 has them beginning to talk about how they might be able to teach students if they have to close for a period. We also get snow days most years due to either snow or ice... I don't understand why, in 2020, one or more startups haven't started to make cheap and flexible software for schools to be able to use for situations like snow days which could easily be expanded to situations like this Covid-19 situation or some inevitable future outbreak.

I mean... people in the United States already teach students in other countries remotely on the side, several of her friends that are now stay at home mothers teach students in Hong Kong remotely for example.

Obviously it's not great as a permanent solution because:

- an alarming number of students in the U.S. rely on the school to feed them 1-2 meals a day because they just don't get it at home

- some students simply can't learn without a teacher physically present

- ?

but it just amazes me there isn't a standard software package or two for this. Especially as a lot of schools have gone to issuing tablets/Chromebooks over the past several years. Software already exists for assignments and tests, why hasn't someone just made a proper classroom app. Video for the teaching/lecture with a way for the students to query the teacher during the lesson with specific questions, then archive the video for the duration of the course so students can go back and revisit the lesson as desired.

- Tornado damage

- Hurricanes

- Snow/ice related closures

- Outbreaks

- Temporary illness in an individual student, students with compromised immune systems, students that are unable to easily attend for a period due to injury

There has to be something like this out there, is anyone aware of anything. This could also easily be adapted for colleges and non k-12 (or comparable) and non-university type institutions.