This is a website made by a teacher for other teachers and their students. Everything here may be used in your classes free of charge. The site uses no cookies or trackers. It collects no data. It hosts no advertising.
Everything is written in HTML and Javascript, and so should run just fine on a Chromebook. Your students may need adjust their screen size to make things look right, but things will work even if they don't.
There is a Teacher Notes button on most of the programs. This will tell you everything the students need to know (that isn't already obvious). I have learned that students, or anyway, my students, will not read this stuff, no matter what. The buttons started out saying Help, but nobody ever pressed one. I tried Press for Snark instead, but that just terrified them.
Noragulfa is the imaginary home of the imaginary friend my children shared with the children down the street when they were all very little. Whatever possessed them to be so avidly discussing noragulfa.com when they were five and three, I have no idea. But as soon as I heard them say it, I determined that some day there actually would be such a web site. Where is Noragulfa? What does it look like? It is far, far away, and just maybe looks a little like Lake Pukaki with Aoraki in the distance.