1. SMS Pols - A tool to do polling with SMS facilities that could help students to reply to a question or can be used as a back channel.It only costs of a txt message. This eliminates all the other sophisticated devices, hiring etc.
This is another tool that can be used as a chat room. The participants can join the room and chat about a particular problem or brainstorm ideas.It also can be used as a backchannel for a class or a conference
3. Google presentation (https://docs.google.com/presentation/d/1s5BxhnmUDMgo5U0PAU5z6a-ADIrdjyRMRol5lwiCdoI/edit#slide=id.g1be17e3c_1_85)
Google documents, presentations are great ways to work collaboratively with a group of people.