Crushare is an Android app that allows you to deliver multimedia messages to any device in the nearby that is equipped of the app, without authentication and without the need of having nearby users in your contacts or similar.
It is though for those situations where a number of people meet for the first time at an event (or even do not meet at all, think of a concert, can you say that you have met everybody there?) and they have the wish of share some contents (opinions, photos, ...) without sharing any personal detail.
Just point your browser to the APK file to install and start playing with this.
Contact me at mirco.soderi@gmail.com for comments and questions.