Good Gear Guide
In Pictures: 9 Top iPhone and iPad productivity an...
OmniFocus lets you keep track of tasks using project, place, person or date as criteria. You can create shopping lists, agenda items for your job, home projects--almost any task imaginable. Tasks are organized by goals using projects, which are then more effectively accomplished using contexts.
Tasks can be synchronized with other users of OmniFocus through Omni's free Sync Server or other WebDAV servers. New tasks can be added anywhere within the app. Large tasks can be broken up into more manageable steps, which can more easily be completed and tracked individually within the app.
In Pictures: 9 Top iPhone and iPad productivity and time management apps