Habits looks simple but Ive found it very useful. The best features are that you do not need to fix specific dates, just number of times a week etc if you like. So much more flexible. I also like that it calculates and shows the success rate (percentage).
However, while using the app I still find myself missing certain features, such as:
1. The ability to jot down a note or journal. For instance, I created a habit to be more patient. On days when I felt Ive failed in this, it would be helpful if I can enter a note to detail how Ive failed that day.
2. Password protect would be nice. Im a very private person but the iPhone is a very popular phone that my friends are always borrowing to play with :-p
simplyi about Habits