APK檔係android system既檔案
通常你係google play download o既野都係呢種檔,
for d android phone(samsung etc.)to use
如果你要用pc黎開,就要download一個android system模似器, called bluestack
then u can open apk games or files.
BLUESTACK'S WEBSITE: http://www.bluestacks.com/
(Window XP/VISTA/7/8)
(MAC OSX)