Only todo list I know of that estimates whether you can meet your deadlines on time given your schedule and life needs. Grabs empty time slots on your calendar and subtracts estimated time it takes to finish tasks so you know if you actually have too many things to do. Built with React JS and Google Firebase.
See https://todo-medium.web.app/ for more details.