Welcome to Gaia! ::

I don't know if any of these are "learning" tools perse. But they're fun!

eigen vector/eigen value calculator
http://www.math.ubc.ca/~israel/applet/mcalc/matcalc.html

phase plane grapher
http://www.math.rutgers.edu/courses/ODE/sherod/phase-local.html

Laplace transforms (super helpful cheat sheet on tests...if you're allowed to use it that is!!!!)
http://www3.shastacollege.edu/tmasulis/Math 4B/Laplace Transforms.pdf

function plotter
http://www.univie.ac.at/future.media/moe/fplotter/fplotter.html