You now will have another flight option to/from Athens to Mykonos and Santorini..  Greek Crete based airline Sky Express is launching two new routes from Athens starting April 21 2016. All passengers also are entitled to use the “Business Lounge Melina Merkouri” in Athens. Nice bonus!    I checked their website. It has an english option on the home page. It’s not as easy to check schedules as Aegean and Olympic, but worth giving it a try.  Here’s a comparison site for flights    http://www.skyexpress.gr/

Try here for more flight information.