Upon recent usage of ContinuousTests with VS2012 I have decided to uninstall. There was too much friction to get it running. I believe it needs an update to support VS2012 properly.
It currently supports NUnit, xUnit.net, Machine.Specifications and NSpec, but the roadmap shows that support for all major testing frameworks is planned.
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.
NCrunch is worth every penny. $159 is really not that bad considering the effort put in by Remco to integrate it seamlessly into VS; which is really not easy. That when combined with the metrics it provides make it a simple decision in my opinion.
NCrunch is an absolutely good product, a bit expensive though. The suggested alternative (ContinuousTest) does not work very well, as it doesn't have line by line coverage, total code coverage metrics and it complains about properly referenced NuGet packages in large solutions (works perfectly fine with NCrunch).
NCrunch also has a seamless integration with Visual Studio which makes coding even faster and more fun, and you know when you met all criteria specified in unit tests while you are coding, without the need to press any button.