Persist puts you in complete control of your audio with a variety of volume controls and settings.
Flexible presets 
Apply your favourite audio settings in one tap. Quickly silence volume levels at an appointment, or at night for a comfortable sleep. Presets can be scheduled to automatically apply at any time or location.
Volume locker 
It's the best way to prevent volume changes when bumped in your pocket, avoiding unexpected bursts of sound or missed calls. Using the “pocket locker” feature, you can automatically prevent accidental changes by locking the volume when your screen is off.
Fully interactive widgets 
A wealth of features at your fingertips. In an instant, you can change volume levels, apply presets, and much more, directly from your home-screen.

FEATURES
Create scheduled presets to easily apply your favourite settings.
Lock each volume level to prevent accidental changes.
Easily access volume controls and presets via notification shortcuts.
Change ringtones for alarm, ringer, and notifications.
Switch the ringer mode between silent, vibrate, and normal.
Control vibrate settings.
Separate or link ringer and notification volume (android 2.3 and below).
Perform various notifications such as a vibrate or sound when the volume is locked. 
View and change a variety of volume levels.
Alarm
Bluetooth
Media
Notification 
Ringer
System
Voice (in-call)

Fully interactive home-screen widgets
1x1 Preset - apply a set of audio settings
1x1 Preset list - easily apply any preset
1x1 Volume locker - change or lock volume levels 
1x1 Vibrate - switch vibrate settings for ringer and notification
1x1 Ringer mode - change the ringer mode
4x1 Dashboard – a slew of interactive volume widgets

NOTE: To access widgets, the app should not be installed to your sd-card, and some android versions may require a reboot for widgets to appear on your widget drawer.

PERMISSIONS
Full network access/view network connections – Bug reporting, google maps, usage.
Modify system settings - Change advanced volume settings
Coarse and fine location – Detect location changes for scheduled presets
Control vibration - Notifications
Run at startup - Restore settings after startup

Screenshots: