This application lets you to search tweets on the basis of HashTag. For example, Consider the following case, I tweet something like, "I feels good while writing WinJS for WIndows 8 application... #WInJS #Windows8." Here in, "#Windows8" and "#WinJS" are considered as HashTags, you can find tweets using these hash tag.
Suppose someone tweets, keeping the name of your company as HashTag, now this application will let you know who tweeted that and what. Isn't that great to know who is talking about you and in which part of the world? Trust me, you will find it interesting, very interesting indeed.