Todo's is a popular to do list app that gets the basics right. You have the usual array of tasks, sub tasks, and notes that you can add to help remind yourself of what you’re supposed to do. There is also cloud syncing so you can access your tasks on a variety of devices, including desktop, web, and tablet. It has a sleek interface and built-in support for Cal Calendar if you want to kill two birds with one stone. It’s powerful, it’s simple, and most of its features are free. It's definitely one of the better to do list apps.