get app store rank
cron_rank:
get the rank through irank, called by crontab
irank:
get and view the app store top rank
version 0.1
usage: $0 <command> [options ...]
<command> Command to be executed
Valid commands are:
get get the top rank from appstore
usage : $0 get cn|jp free|paid|grossing|weather
view view the specific app's rank
usage : $0 view cn|jp free|paid|grossing|weather [app_name [ _change_times]]
diff record the changes of rank
usage : $0 diff cn|jp free|paid|grossing|weather