Hello JohnC206,
While there is no direct way to control volume for each individual app on iOS, you could create an Automation in the Shortcuts app on your iPhone that adjusts the volume to a preset value when you open certain apps:
- Go to Shortcuts -> select the "+" button
- Call the shortcut something like "Volume C" and search for volume in the Actions panel and add a descriptive icon (perhaps the speaker with one bar)
- Select "Set Volume" and set a volume level for this shortcut
- Repeat these steps for "Volume B" and "Volume A," selecting higher volumes in each turn
Then...
- Select the Automation tab in the Shortcuts app
- Tap "+" and select the App automation
- Select the app for which the volume will be controlled
- Choose "Is Opened" for the condition and set to "Run Immediately"
- Next, choose one of the volume shortcut options you configured in the last section
- Now, when this app is opened, the volume will adjust automatically
- Repeat the steps as needed
I know that this will create a static volume value for each app added, but at least you don't have to manually adjust the volume when jumping between apps. I assume this is what you are trying to achieve, generally speaking? I know that iOS only allows one source of media at a time, so you can't adjust each app individually and simultaneously.
Sorry for the long response, but I hope this helps.
Have a nice evening.