If you use Apple's Reminders and Calendar apps at all, I highly recommend Fantastical. It works really well. I love being able to see my one-off todos and chores and appointments all in the same view.
The one thing it might lack is guidance to organizing projects/subtasks/dependencies. But luckily I don't need those in my calendar.
The one thing it might lack is guidance to organizing projects/subtasks/dependencies. But luckily I don't need those in my calendar.