Browser plugins for viewing mathematics and for submitting automata in quizzes and exams.
More detailed instructions on installing and using these can be found here.
JFlap with my own bug fixes. (Last update: 2/1/2019)
Cupillari, The Nuts and Bolts of Proofs, 4th ed., available online via Virtual Library of Virginia (VIVA)
Sundstrom, Mathematical Reasoning: Writing and Proof