This is a good web tool that allows you to create a personal startpage with your most important bookmarks and RSS feeds.Easy to use, reliable and completely (ad) free.
3- WikiTube
WikiTube is a cool Chrome extension that adds YouTuve videos to Wikipedia entries. When installed, you will be able to watch videos related to Wikipedia items you are reading.
5- ClassMint
6- Azendo
7- Twiducate
Twiducate is the perfect solution for elementary and secondary students. Rather than having your students sign up and enter an email address, you sign up and create a class code.Using this code, your students log in to your class network.Here, they can answer questions, collaborate on problems, and even embed pictures and videos. As a teacher you have full control over the network. You can even add other teachers!
8- Examtime