1. By typing "*#*#4636#*#*" you will be redirected to phone information menu. This code allows you to check information about your phone, battery, battery stats and WiFi.
1.1 Phone Information - Here you can check your IMEI number, Signal strenght, cellinfo and connection type. Also you can run Ping test too.
1.2 Battery Information - This page shows your battery properties like: battery voltage, temperature, battery technology and device running time.
1.3 Usage statistics - This one displays your last app usage period.
1.4 WiFi Information:
- Wi-Fi API - Here you can disable current WiFi network, disconnect connection, get information about connection and other stuff.
- WiFi Configuration - On this page you can check information about connected network
- WiFi Status - Read about connected network and run Ping test
2. Typing this secret code "*#06#" you can easily check your IMEI number.
3. Calendar *#*#225#*#* - check your events in calendar
4. Debug info for Google Play Service *#*#426#*#*
5. Access Google Partner Setup *#*#759#*#*
6. Access email debug information *#*#36245#*#*