Brief list of useful online tools for #LaTeX (#TeXLaTeX) users:
https://www.unicodeit.net to use Maths symbols on pages that do not support LaTeX (e.g. here)
https://www.tablesgenerator.com/latex_tables to generate tables without going mad
https://editor.codecogs.com to get an image of your equations you can copy-paste
https://detexify.kirelabs.org/classify.html to find what is the command for that less-used symbol you can never remember
https://www.doi2bib.org to get a well-formatted revtex bibliography from the doi of the paper
Do you have more to add?
@j_bertolotti this dev branch of excalidraw supports Latex: https://math.preview.excalidraw.com/#json=9tUeRK76h1BT2Y7CPwv-H,QuWZSIqkCnU6ydKTYkXbqQ
@baptnz @j_bertolotti http://www.overleaf.com allows you to create latex documents online. My collaborators use it so I started using it.