On some mobile platforms there are alphabetical lists that use the letter as a title. As you scroll down the list the current title follows you until you reach the next one at which point the current one is pushed up and the new title docks to the top. This snippet emulates this functionality.
Forked from Chris Spittles's Pen Multiple Sticky Titles with CSS and JS.
A Pen by Captain Anonymous on CodePen.
I am looking for this exactly functionality but your code doesn't seem to work for Mobile.