About Ringer
Ringer application sets the ringer mode based on the selected contacts for ringing. Ringer app is used to enable ringing mode for the particular added contacts even if your phone is on the silence mode. Ringer application has the capability to synchronize your active contacts (to ring as set by you) and restore when you install this app again after UN-installing it.
by X####:
Very useful. Now with tone you can identify caller