Main background image:
http://unsplash.com/

iPhone screenshots:
https://dribbble.com/shots/1428271-iOS7-Challenge-App

iPhone PSD:
https://dribbble.com/shots/661417-iPhone-holding-hand-Free-PSD

iPad air PSD:
http://www.tricky-photoshop.com/apple-ipad-air-psd/

Font-Awesome:
http://fortawesome.github.io/Font-Awesome/

Google Fonts (Roboto & Noto):
https://www.google.com/fonts

Bootstrap:
http://getbootstrap.com/