Social Media Use In Teens

I'm giving a presentation next Monday to foster care and adoption social workers. The topic is Internet, Social Media and Gaming In Teens.  I'm trying to do some last minute research. Please post in the comments what apps your teens are using the most for social media, what are the dangers you've encountered or what are the positives you've seen. (Reblogs will help a great deal as well to get as much info back) Thanks in advance! 😃👍🏻 Edit: I'll be compiling a post on the top 5 apps parents need to be aware of and some resources to help after the conference