SmartRingController sets the ringer volume according to the ambient noise when an incoming call is received. If the silent mode or the vibrate mode is enabled the app does not change the volume.

SmartRingController also
... controls the vibration (pocket mode).
... handles notifications.
... reads out notifications and caller names. (e.g. with a wired headset)
... supports a "flip for silence" gesture.
... decreases the ringer sound on shake and when the device is unpacked.