So, what has replaced instant messaging _in a meaningful way_ for teenagers? I hear Snapchat, but I don't think that it's actually filling the gap. I've heard folks say YikYak before, or whatever the fuck it was called, but that app was a pile and I'm pretty sure it died anyway over privacy violations.
What's out there that is directly connecting teens online today? Please tell me they're not all walled in to Facebook without any alternatives...