I just discovered VYOU. You can receive messages or record video responses. I could see it being used for students to answer or respond to the teacher or to other students. They could practise their pronunciation and send messages to others in the class... Teachers could also use it as a response box for students to send their questions to. Make them think you are on call 24/7! With a bit of imagination, I think it could be used in a lot of innovative ways in the EFL class. Would love to hear any of your ideas on how you would use this tool.