Sometimes you just need to make a graph. If your TI-84 isn’t handy, Desmos Graphing Calculator is a good backup to have. The app accepts both functions and tables of x and y values as inputs and ...

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).

While Calculator won’t do your Calculus homework for you, it’s at least a lot easier to navigate than your handheld graphing calculator—prettier, too, and a lot cheaper.