IOS has a powerful ringtone library. But It only could be used to system apps, like phone.message.etc.And also some apps don’t have a notification sound. All the notifications sound the same, you can’t tell the one which you care. With this tweak, you can select a sound from ringtone library for every push-enabled app.
To assign a sound, go to the Notifiations panel in Settings, choose the app from the list and configure the sound played with the new option added to the bottom (see the screenshots)
Sounds can only be assigned to app notifications that support audible alerts ‘sounds’