Secret codes reveal information on your iOS or Android phone
Punching in the special code will allow iPhone users to view signal strength in decibels instead of dots
Instead of the dots signifying signal strength in the upper left of the screen, you will see a number representing decibels. A reading in the range of -40 to -80 is very good. Any reading of -110 and lower would represent a very poor signal. To return to the dots, use the code again to open the Field Test screen and close it with a single tap on the home button. Other codes include the *#06# that will show your phone's unique IMEI number, and *#33# will show you if your iPhone is enabled for voice, SMS and data.
Android codes are harder to list since many are manufacturer-specific. We can pass along a couple that should work on all Android devices. To view multiple screens of information pertaining to battery usage, Wi-Fi configuration and more, punch in *#*#4636#*#* on the dialer. Dial *#*#1472365#*#* to see information about Google Calendars.