App Specific Volume Settings

Let’s face it — some apps are louder — or quieter — than others. There’s always that one app that has you rushing to mute your phone, only to have to turn it up again later.
Some apps allow you to adjust their volume, but not all of them. Being able to find any app in Settings and adjust its volume would create a universal space for making changes. Apple could even let developers add separate sliders for options such as music, sounds, and voice.