If you need task management software or a to-do list solution that works with a team, this is not your best option. (Look at Basecamp, Trello and a variety of other options)
If you need a project management tool, this is also not your best option. (Look at OmniPlan)
If you simply want a simple to do list (not multiple lists, recurring rules, categories based on context/project/etc.), then use Apple Reminders or Google Tasks.
This is a robust tool, for personal task management.
Personal Task management. I need a place that I keep all my todos - not my inbox, not my calendar, not my notes - a specific place just for to do lists. OmniFocus has been my place for 7 years now.