Facebook Inc. FB on Tuesday said it is working on a version of its Instagram app for kids under 13, who are currently not allowed to use the app because of federal privacy rules. “Increasingly kids are asking their parents if they can join apps that help them keep up with their friends,” Facebook said in a statement. “Right now there aren’t many options for parents, so we’re working on building additional products – like we did with Messenger Kids – that are suitable for kids, managed by parents.”