Way of Life
If you're a fan of chains.cc I suggest you give serious consideration to Way of Life. It is a much more rounded habit forming/breaking app. The charts are precise and easy to read, the diagrams have multiple views depending on your taste, and having the ability to skip days so you're not beating yourself up over missing a day at the gym for a wedding is a major plus compared to the competition being so black and white. With other apps, seeing a blemish of missing 4 days of a daily task due to illness is still seen as being lazy. Not with Way of Life – and why I upgraded from the free version to the pricey $4.99 Pro.
As you collect more and more information you will be able to easily spot positive and negative trends in your lifestyle, without restrictions.