Overleaf - The online platform for scientific writing. Overleaf is free: start writing now with one click. No sign-up required. Great on your iPad.
Streaks - The to-do list that helps you form good habits.
TeXworks - The TeXworks project is an effort to build a simple TeX front-end program (working environment)...
Taskful - Deadlines, meet your match.
Fidus Writer - Fidus Writer is an online collaborative LaTeX editor especially made for academics who need to use...
ToDoList - Windows desktop application to stay on top of your daily tasks.