Mobile systems, applications, and services and co-located workshops : MobiSys'15, proceedings of the 13th international conference ; DIY Networking'15, DroNet'15, Future Mobile UI'15, IoT-Sys'15, MobiGames'15, MobiSys'15, PhD Forum, WearSys'15, and WPA'15, Florence, Italy, May 19-22, 2015 (ACM - Association for Computing Machinery, 2015)