How I Use It
I've used this before with classes when talking about information gathering techniques online. It's a search engine for hashtags- so if you type a hashtag you immediately get posts related to said tag from multiple sources and sites. It's not the most educational: as most of the information you gain is from social media (how much can one person learn from 500 tweets about #awesome?) but it's definitely a good conversation piece regarding the concepts of viral internet information, digital citizenship, and information access online.
I wouldn't necessarily use this as a regular teaching tool- because, again, you're getting information from social media sites en mass and the question becomes what to use that for. It can be interesting, and is "fun" to use now and then, but as a resource in class I have yet to really develop a plan utilizing it more than just for a demonstration or two on concepts. I could see it as more useful for people working in the social media field and advertising.