A child's Google Account also allows parents to give them access to You Tube Kids.
That said, the content that's permissible on You Tube Kids has been the subject of a lot of attention recently.
To use Messenger Kids, a parent or caregiver uses their own Facebook account to authorise Messenger Kids for their child.
Enter Messenger Kids, Facebook's new Messenger app explicitly for the under-13s.
Messenger Kids is promoted as having all the fun bits, but in a more careful and controlled space directed by parental consent and safety concerns.
It's not hard to imagine why, when many children now chat with Google daily using the Google Home speakers (which, really, should be called "listeners" first and foremost).
Google Home, Amazon's Echo and soon Apple's soon-to-be-released Home Pod all but remove the textual and tactile barriers which once prevented kids interacting directly with these online giants.
While this is consistent with Facebook's real names policy, the flexibility to use pseudonyms or other identifiers for kids would demonstrate real commitment to carving out Messenger Kids as something and somewhere different. Facebook might not use this data to sell ads to your kids today, but adding kids into the mix will help Facebook refine its maps of what you do (and stop kids using their parents accounts for Video Chat messing up that data).
It will also mean Facebook understands much better who has kids, how old they are, who they're connected to, and so on.
Many children have utilised some or all or Facebook's features using their parent's or older sibling's accounts as well.
Facebook isn't alone in exploring variations of their apps for children.
As far back as 2013 Snapchat released Snap Kidz, which basically had all the creative elements of Snapchat, but not the sharing ones.
Facebook's main app, Messenger, Instagram, and Whats App (all owned by Facebook) are all free to use because the data generated by users is enough to make Facebook money.