Listary is a great little To Do app for the iPhone and iPod touch. I’ve been beta testing it for a while and it quickly became the To Do app I kept using. It has a simple and elegant interface that gets out of your way, and helps you quickly add or complete to-do items and manage task lists. It also syncs with Simplenote, making it quite diversely useful—whether you’re collaborating on a project, sharing a shopping list or just want to access your information on another devices. Highly recommended for anyone looking for a clean, no-frills To Do app. $1.99 on the App Store.