Microsoft needs to Utilize the volume bar more.
For those who use windows phone, we all can agree the volume bar is an amazing piece of work. As of now with it we can control sound, ringer, and music. However, Microsoft can expand on this.
The volume bar is accessible in every part of the OS. It is activated by hardware button that standard on all windows phone. Microsoft needs to add more functionality to it.
For example, a notification center of some kind is on the horizon. What better way for a quick access of the notification center than via the volume bar. Whether through a button that can be placed at the top or on to have a separate bar to come in from the bottom of the screen. There would be no need for a third screen, ugly status bars, cumbersome swipes, pull down shades, nor any gesture that populate and crowd the software.
Another example, quick settings, screenshots, charms(a boy can dream) can be added. (Not necessarily to the top bar but a secondary bar that can come from the bottom)
In conclusion, the volume bar is not used to its full potential.