For Android users to quickly open the development of personnel options engineering mode battery power background service management and other functions;and this is a secret code management tools such as Android phone secret code *#*#4636#*#* to open mode of engineering as well as some MTK Enginerr mode *#*#3646633#*#* code.
You can also from forums or other place to search for your phone special secret codethen used this tool to add and manage.