DelegateLite is a To-do list manager for the Mac, iPhone and iPad. It allows you to create lists of tasks that you need to carry out and delegate them to one of your Address Book contacts. The app has a very good-looking interface, and it is extremely robust. Perhaps, the most interesting aspect of this app is that it allows you to create simple or very detailed To-Do lists. When you add a task to your To-Do list, you can assign a contact to it, set a due date, add a subject (which will be the name of your task), some details, and tags. Then you can set its priority, from 1 to 10; 1 being the most urgent one. All the tasks will be shown in the main window, and you can set them as "completed" by clicking on the checkmark next to them.
The Lite version is fully functional. The Pro version, however, lets you sync your Mac lists with your iPhone or iPad, to export and import data and to see a global view of all the opened lists.
In short, DelegateLite is a nice To-do manager with support for delegating certain tasks to any of your contacts. It has a great design, and it works well.