K-12
Make phone calls, video chat, can be used for classroom activities and personal use.
Con: Must register and download program, and new district permission.
K-12 Evernote works with nearly every computer, phone and mobile device out there.
Students and teachers can take notes on anything and everything. It's FREE!
Con: You must register for the site to be able to use it.
6-12
Teachers are able to give a poll or pose a question to students and allow them to use their cell phones to answer. Students will use text messaging to answer.
Cons: its costs money and you cannot determine whose reponse is who.