What's the difference between Fetion and Flying Pigeon? Is there no charge for flying pigeon mobile phone exchange?

Fetion is a communication software specially developed by China Mobile for mobile users, which is divided into computer client and mobile phone client. I don't know if the flying pigeon signaling you mentioned is the software that I know is specially used for communication in LAN. Generally speaking, if you all use computer clients, there is no extra charge for sending messages to each other. But if you use a computer client to send messages to each other, and he replies directly by SMS, there will be a cost. If you use a mobile phone client, only the generated traffic will be charged. As far as I know, flying pigeons are generally used for computer local area network communication, as if there is no mobile phone client.