This is a simple tool to facilitate explaining things with equations.
Share your screen with your audience using, e.g., Zoom. Type below and hit enter. Put TeX expressions between dollar signs, e.g., $x \mapsto x^2$ becomes $x \mapsto x^2$.
To go back and edit something, click on it or use the up/down arrow keys.
To add new macros, type them in the box below (e.g., \renewcommand{\epsilon}{\varepsilon}), then click "Save and Update". Don't type dollar signs here. Next time you open this webpage on this computer, your macros should still be here, but I recommend you save a copy of your macros elsewhere just in case. If you want to remove a macro, unfortunately you'll have to also reload the webpage.