This tool is intended as a utility for use during the BizTalk development process, the basic operation of the tool revolves around the "save", "restore", and "clean" commands. "save" followed by an name (this would be an application name you make up yourself) will save all the BizTalk artifacts you are currently working on into a directory with the same name as the application name you pick. The "restore" command will restore whatever is in a btsnapshot appplication directory back into the management database. The basic use case of the tool is when you've come to a point in your BizTalk development when you need to undeploy and deploy all of your artifacts due to some change you've made. "clean" is useful when you just want to remove everything you have deployed and configured to start working on something else.
You can read about this tool in pretty good detail from the blog entry - the point is to have a simple front end and API to the Enterprise Single-Sign On Server to store configuration data in a safe (encrypted) way in a distributed system like BizTalk
Again you can read the purpose of this tool from the blog posts ( here is an interesting update ) the basic idea however is to have a way to add arbitrary context properties to messages flowing in and out of BizTalk
A way to see the schemas you've deployed into BizTalk as well as a way to generate CSharp or VB.NET code to be able to easily use XML Serialization to generate the XML to send into BizTalk