Children are using technology at ever-younger ages. About 15% of kids under the age of 11 have their own mobile phone, according to eMarketer. The Pew Research Center’s Internet & American Life Project reported last summer that 16% of kids 12 to 17 who are online used Twitter, double the number from two years earlier. Most of the Tweens simply want to avoid bumping into Mom on Facebook. As families grapple with how to use social media safely, many marketers are working to create social networks and other interactive applications for kids that parents will approve.