Zte Z557BL User Manual page 140

NOTE:
The notifications of some apps cannot be turned off. Content
hiding is only available if you have set a pattern, a PIN or a
password as the screen lock.
Sound
Adjust different types of volume (see Personalizing – Adjusting
Volumes), set up phone ringtone, alarm ringtone and notification
ringtone (see Personalizing – Changing Ringtone and
Notification Sound), select touch sounds (see Personalizing –
Turning On/Off Touch Sound), or control Do not disturb access.
Apps
Press the Home Key >
installed on your phone and manage them.
Tap > Show system/Hide system to show/hide system
apps in the list.
Tap > Reset app preferences to reset all preferences. (You
will not lose app data, but app preferences will be restored to
default.)
Tap to configure apps.
In the app list, tap an app to see its information. The following
options may be available:

FORCE STOP: Stop the app.

UNINSTALL: Uninstall the app.
> Settings > Apps to see apps
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