Since NCrunch has left the free market, I was looking for a similar tool for code coverage marking, and continous testing like NCrunch
edit: I'm using VS2012
update:
I've been using ContinuousTest for a while now, it's OK, but I think it lacks feedback when I write code. The feedback is good when I write tests, but when I break a test (while editing source code) it won't tell me that the test broke (in the margin, like it does for NCrunch). So if anyone knows other tools, I'm still listening.
NCrunch is a fantastic tool that I discovered while it was still in beta, as a developer I try to do my best to support people that are doing cool projects. If people were using NCrunch and liked it, I'd encourage you to purchase a license.
Stuff like that takes a lot of time to develop and less people will be creating the cool tools you love if people aren't willing to support it.