Things
This popular Apple program is now in iPhone form. With to-do lists and options to list ideas that don’t yet have actions, it’s easy to use. Also syncs to Desktop version of Things.
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Action Method
My project management system of choice, Action Method allows you to organize projects by specific action steps, add target dates and keep a variety of projects organized in one place. Also syncs to a web-based version of the program, meaning you can take your to-do list anywhere.
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SmartTime Free Tasks and Schedules
Keep track of tasks and schedules easily online. Upgrade to the full version for email integration and the ability to transfer and add projects to your Google Calendar.