In Spring 2013, I made a simple webchat website called Modnar. Made in PHP all it did was add messages to a log. The server it was located on was shutdown for "abuse". Now in Fall 2014 I set out to fix all the problems with Modnar 1.0. The original purpose of Modnar was to chat with friends in the same room at school without getting in trouble.
Modnar 2.0 is Server-Free, anonymous, all specific to individual networks.
No matter how many messages are sent, no databases will overflow.