I’m using Du battery server over 3months and its very bad application.when I open it its shows me that my battery was not optimize so when I optimize its shows my battery was 20min extra power but it dosend work.the concept was not good no states bar on it.its designe was good but not works for me.it has some verry cool features like optimize, power saving, theams but they are not works.some functions are good but not that much good.it is very un usefull app for me. it is my personal experience in this app