Check out the list below and as usual share with us your suggestions or additions
1- Poll Everywhere
This is my favorite. It allows users to easily create polls and administer them to an audience ( students in our case ). It also has a mobile app that works on iPad.
This is another polling service that you can use to create polls for your classroom. It is very simple and easy to use , just head over to its main page and start filling the boxes provided there.
This tool lets you maintain a back channel chat with your students. Students can use it to comment , ask questions , or post their feedback about their learning in the class.
4- SimpleMeet Me
This is an awesome web service that enables users to chat with others without having to install any software or even registering. You can use it with your students to gather feedback.
This is a tool that you can use on your classroom blog or website to gather feedback from your students. It is very simple and has a user friendly interface. Students can use it to post their questions and comments online.