Good GTD/todo/tasks app
I like Clear. 

It has reminders that can be snoozed. The snooze time is not optional (unlike the default Reminders app). When you snooze, it simply snoozes for 15 minutes. 

You can create any number of categories under which to put tasks. 

You can very easily prioritize tasks. 

It doesn't really have a "today" or "this week" view except as a widget in Notification Center. 

The UI is unbelievably easy and efficient to use.