Profoundly

While it might seem like a weird software solution to allow people to send anonymous messages, we have to keep in mind that they are designed for Facebook friends, and not for just anyone.
 
Profoundly uses its own platform for messaging and not the actual Facebook Messenger. It’s a great way to start a new conversation or simply to tell people how you feel. You can share your thoughts anonymously by stories and receives messages from your friends.
 
The developers are promising that the user’s identity remains completely protected and anonymous, and the user’s information is secured and not shared with third-party companies.