I2P stands for Invisible Internet Project and is an overlay network that offers the solution for a communication in a secure way. With this network, you can surf the web, chat or write on your blog in an anonymous way. The software that you can use to do so is totally free, is open source and is published under multiple licenses.
I2P can be used in general networking, for file sharing, for chatting and even for sending emails in an anonymous way. It can be downloaded from Google Play and be use on Android. If you want to browse the web without any fear, this is the network that gives you this opportunity.