Don't act like you don't know Charli XCX. She's been part of two MAJOR summer anthems: Icona Pop's "I Love It" and Iggy Azalea's "Fancy." Her new single, "Boom Clap" is just as catchy AND was in "The Fault in Our Stars." She's been here the whole time and now you know!

Want more Charli XCX? Check out her iHeart radio station here!