Like it or not, smartphones have become an indispensable part of your average teenager's life. To gain a better understanding of just what today's youth are actually using them for, The Huffington Post interviewed 14-year-old high school student Casey Schwartz about her iPhone habits. Unsurprisingly, a large part of her activity revolves around messaging. Casey and her friends have run the gamut of messaging clients, cycling through Snapchat, WhatsApp, Skype, and others to facilitate their daily group chats.

Apple's iMessage is among the few apps that have stood the test of time. In fact, it's proven a requirement for anyone hoping to maintain a real-world relationship with the teen. When one of her friends lagged behind in upgrading to an iPhone, she was effectively shut out of Schwartz's inner circle. "Not because we didn’t like her, but we just weren’t in contact with her," she explains. Facebook (where she's tallied over 1,000 friends) and Instagram also see obsessive levels of use, and the 14-year-old has even weighed in on Yahoo's big Tumblr buy. "I'd rather it was how it was before because I'm afraid they're going to change it and make it worse." For the full portrait of a modern teen's iPhone usage, head over to HuffPo.