dotfuscator StackViewer
Visual Studio comes with Dotfuscator Community Edition - a free tool to obfuscate
.NET binaries.
The gotcha is if a user sends you an exception with stack trace from your dotfuscated
application, you need the full version of Dotfuscator to view it. DFStack is a cheaper
option, but it wouldn't work consistently for me, and theres no source code available.
So heres a free open-source obfuscated stack decoder.