Facebook has launched its Messenger Kids app, geared toward children under 13. The messaging app allows parents to set up the account and approve their children’s contacts. The company says that the free app has no ads or in-app purchases. It was released as a preview on iOS devices and will be available to a larger audience at a future date. “We’re going to see how kids are using it, and that will allow us to add updates in future versions as necessary,” a Facebook spokeswoman said. Under current law, people under 13 cannot legally sign up for Facebook.