They require a phone that can log into an App store, so unless parents can work around that, then yes?

Nonsense. My kid just started kindergarten this past year - I've never been required to log into ParentSquare through a GMail address and I have only ever accessed it through a browser on a laptop.

(Damn, I failed at my attempt to stop posting.)

The web is no better than phone apps when it comes to data gathering. Maybe the data is a little fuzzier, but you can be assured it's being gathered all the same as it is in phone apps.

Yes it is.

It is not perfect but you have much more control on which domain you connect to and/or which js you execute.