Facebook has launched a new version of Facebook Messenger, aimed at children under the age of 13. The app, called Facebook Messenger Kids, works much like a trimmed-down version of the mainstream version of the app. The biggest difference is that it’s designed with parental controls in mind. Accounts have to be set up by parents, and kids can only talk to a pre-defined list of contacts. These can be relatives, who can use the ordinary Facebook Messenger app, or carefully-chosen friends. The home screen shows a list of who they can talk to, and who is online to chat.