<http://schema.org/thumbnailUrl>
<http://www.imore.com/sites/imore.com/files/styles/thumbnail/public/field/image/2012/09/Period-Tracker-vs-iPeriod-vs-Period-Diary--period-tracker-apps-for-iphone-shootout.jpg?itok=mUSifhow>
<http://www.imore.com/comment/310810>