Secret Codes is an Open Source application allowing you to scan your device and discover hidden functionalities.
A secret code is defined by this pattern: *#*#code#*#*.
There are multiple ways to trigger them, but the simplest is to directly enter them in the dialer app.

From version Secret Codes 2.0:
All versions
Secret Codes 2.0
April 16, 2016

Version:2.0

Uploaded:April 16, 2016 at 7:21PM UTC

File size:1.41 MB

Downloads:1,678