Mastering your to-do list can seem like a Sisyphean task. But a good to-do list app should help you regain control over your routines and keep chaos at bay.Our to-do list app picks, Todoist, TickTick, and the Apple-exclusive Things 3, are a breeze to use, have thoughtful designs, and feature flexible organization schemes, so you can conveniently hop in, address your obligations, and enter new tasks — then get right back to the doing.