The calculators are free to the public and can be accessed with a computer, tablet, or other personal device. VDOE said hand-held calculators (more old-school approach) only would be used by students ...

On Android, consider checking out Graph 89 Free —though you’ll need a .ROM image for it to work (something you can extract from your existing graphing calculator or surely find elsewhere).

Google has rebuilt Chrome OS's built-in Calculator app, making it available for all devices, not just Chromebooks.