Having a Tagboard supports a "backchannel" so that people can share their thoughts and ideas as they participate in the conference, connecting with each other via Twitter. You can find out more about Twitter backchannels in these articles: Twitter Backchannels.
Tagboard tracks Twitter activity and then gathers up activity related to a specific tag, and it can also gather content from other social networking services where hashtags are used. For example, here's the #OUTechExpo Tagboard from January 2016; you'll see that it's mostly Twitter, but there's a Google+ item there at the moment also:
With a free Tagboard account, you can create a Tagboard and customize it for one hashtag, so if you want to use a service like this for a hashtag related to your classes, for example, it would work nicely. You can use Twitter for a class backchannel much like the backchannel at a conference!
NEXT STEP => Next up: Twitter visualization tools!