So, to conclude: Treat others on Tellonym as you want to be treated. You don't have to fear that you are going to be revealed unless you commit a crime on Tellonym (bullying is a crime). Only law enforcement agencies are able to track down a person that sent a Tell and only do so if somebody filed a law suit.
External pages that claim to know who sent a Tell are completely fake. We do not work with external services that claim to know the senders of messages and are never going to do that. Anonymity is an important part of Tellonym and we know that. We know that you trust us and we won't let you down.