Recs.
Updated
SpecsUpdate
Pros
Pro Cloud sync
Users need to create an account for Things Cloud (the account can be created from any device). Once signed up, cloud sync will be active, and you’ll have to login on all of your devices to complete setup. From that point on, syncing happens in the background. It is invisible and always reliable.
Pro Project support
Things 2 has a projects feature that allows you to organize your tasks together. You can select a project you need to get done and Things helps you focus on each task to get it done. You can even group projects together to focus on the most important aspect of your life at the time.
Pro Absolutely unique way of handling repeating tasks
Repeating tasks create a child task every time they are due, which can be postponed or deleted at will, without changing the repeating task itself.
Pro Defaults to start date; deadlines and reminders (timed alarms) are optional
Most other task management apps use deadlines and reminders very prominently. In Things, it is really easy to set up a start date but takes a little more effort to set deadlines and reminders. This keeps the alarm system on a low and therefore sensitized profile.
Cons
Con No supported time based/location based alarms
Other apps have these abilities, and they are very useful. Especially for a $10 app, it would be great to include these premium features.
Update: Things3 now supports time-based reminders.