There is one, it's called PhotoAcute Studio, and I've been using it for a long while now. Not only does it stack images for noise, but also resolution and other things, under the right circumstances you can effectively double the resolution of your camera while reducing noise.
The software needs a profile for your specific camera/lens combination, but if you make your own profiles, you may even get a free licence to use the software.
what i like is the comment about how averaging increases the bit depth. sounds all too good.
Well, sort of... The bit-depth, dynamic range, and noise of any given digital camera are all linked together. The bit depth of the analog-to-digital (ADC) converters of the sensor will determine the maximum theoretical dynamic range of the sensor, 14-bit ADC results in 14 stops of dynamic range for most modern cameras, but it becomes hampered by the noise floor. The cleanest digital cameras of today, like the Nikon D800 at ISO100 have 13.5 stops of DR, this means that at ISO 100 you can push the blackest blacks up to a brighter value and they will retain detail.
If a camera were capable of reproducing all 14 stops with no electronic or photon interference, it would basically be as clean as CGI, and you wouldn't see any noise even if you pushed the blacks into the highlights... at which point it would probably make sense for the industry to switch over to 16-bit tech and reach for 16-stop cameras. Unfortunately, physics may* not allow this, even if the tech is good enough. Photoshop's own 16-bit mode is actually 15-bit, because Adobe believes that no one could possibly make use of that many bits (but anyone who has used computers for any length of time knows how those kinds of assumptions turn out!). *I do not claim to have a good understanding of physics.
So what I'm saying is that averaging doesn't increase bit depth, but it does reduce the noise floor and improves the dynamic range, which in turn, makes actual use of the bits the data is assigned to. (The 5D3, for example, may manage only up to about 12.5 stops DR, so it's 14-bit ADC's only serve to quantize the noise floor; if it had 12-bit ADC you most likely wouldn't notice the difference)