Since it's mostly been covered by the other posts, just a few quick points/comments:

This software shouldn't be needed.

You *are* explaining cross platform file sharing, just using an additional piece of software in your solution. The sharing support built-in, when it works*, is no harder to set up than this process of downloading, installing, and *then* going through the setup steps (as many or more as the set up of SMB sharing).

* there are some common issues that get in the way of the built in sharing (for example, default Win2003 settings and the Samba config in OS X not doing the message signing, etc.)

I think it would be a better service to expose these issues and clearly document how to work around them (and that is no harder than your written steps on using ipconfig from the command line). Plus it brings to light the issues in yet another forum and encourages Apple to fix them, though I suppose pushing a third party software as the solution over the built in does that as well.

And yeah, it's nice to support the efforts of a fellow developer, but it helps when it is solving a problem that doesn't already have good, included solutions. It is an unfortunate (in one way of looking at it) fact that 3rd party developers will have their products obsoleted as the OS makers decide something is important enough to fold into the base offering. It's happened to me before, and it'll continue to happen.

Don't take the criticism too hard though, I just think the effort would have been better spent educating the readers about what is already there.