Producteev - Cross Platform and Free Task Management

Producteev is one of the leading free Task Management applications for Individuals and Teams connected to : Mac (Mac App Store), Web, Mobile, IM (Gtalk, AIM, Yahoo Messenger...), EMail (send tasks to task@producteev.com), Gmail, GCal...

The iPhone application works offline and syncs in the background with the rest of our apps (Mac, Web, Mobile).

As good for very simple to-do lists than collaborative task lists with your co-workers thanks to our "workspace" feature.