Freemium BACKCHANNEL CHAT is a "real time educational discussion tool" that brings Twitter-like conversation to the classroom with a little less chaos. The premise is simple: start a conversation, invite students or collaborators, and chat away. From there participants can share comments and embed web-based media in a completely ad-free forum. Backchannel Chat differentiates itself from similar tools with its teacher-specific features designed to keep tabs on a conversation. Teachers have full moderator control over posting and can easily search or archive transcripts from a specific chat. Students, meanwhile, can "amplify" specific questions, ideas, or comments that they'd like the teacher to address by up-voting a post. There's even a profanity checker in case a few knuckleheads decide to get wordy. The free version allows for 30 concurrent users and a limited number of discussions. Twenty-five Aussie bucks gets you unlimited concurrent users and discussions, plus advanced security options.