Developer apps cydia launchrelease CustomNotificationSound, This tweak works with iOS 8. CustomNotificationSound jailbreak tweak lets you to change Notification sound for third-party apps. The tweak provides users with the ability to use any custom sound for third-party app notifications. The good thing is that it is integrated into the settings pane of each app making it easier to choose custom sounds on the go.
Once installed, you can go the Settings app to set the custom sound for a third-party app. You’ll notice a new option labeled ‘Custom Sound’ right under Show in Notification Center. Tap on it and you’ll be be a able to select from a list of custom sounds that come preinstalled with the tweak.
If you are interested, then you can free download CustomNotificationSound iOS 8 from the BigBoss repository in Cydia. To install this program requires a jailbroken device (see if and how you can do the jailbreak to your iPhone by clicking here) and you need an Internet connection to download the package. This tweak is compatible with iOS 8.0 and later versions of the mobile operating system from Apple.