In case you were debating with your friends this entire week over who is the most popular of the Kardashian clan, we're one step closer to a clear answer: It's Kylie Jenner, and overwhelmingly so.br The iTunes store anointed the 18-year-old and her new venture, Kylie Jenner Official App , as its No. 1 downloaded free application on Wednesday.br It's a huge feat, as Kylie Jenner - who's been making the rounds this New York Fashion Week with trophy boyfriend Tyga in tow - beat out Facebook, Instagram, YouTube and Snapchat in the store.br Kylie has a massive following on Snapchat, as well, so her influence on mobile shouldn't come as too much of a surprise.