some players sit on coc after every 12 hours im 1 of that so i got a idea of double upgrading means if i wanna upgrade a archer tower like my archer tower is of level 6 n i wanna upgrade it to level 7 n i wanna upgrade it to level 8 both at once when when my archer tower is upgraded to level 7 instantly it should start to upgrade to level 8 .hope u like this idea !!!!!DOUBLE UPGRADING!!!! it saves time... :)

