NCrunch collects test coverage for your code while it runs your tests.

This is shown next to your code in coloured markers showing which lines the tests touched, with marker colours indicating pass or fail status.

You can also navigate to any covering tests from any line of code, making it easy to see which tests you might impact with a change.

Full code coverage metrics are also available for your entire solution, allowing you to see where your code coverage is heavy and where it's light.