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).

Windows 10 Build 19546 includes a special Graphing Mode for Windows Calculator that looks surprisingly nice.

Like textbooks, graphing calculators are still a necessary (and expensive) accessory for math and science students in high school and college. Sure, there are calculator apps for tablets and ...