I cant download my photo vault and it says the apps is no longer available. I need those photos in the apps. Os there any way i can recover all the files inside? This should not be happen as users put their trusy in the apps that authorized by apple.

You are going to have to try and contact the developer. They were warned months ago about updating their apps to run on iOS 11, and you were warned about apps that were no longer going to work in iOS 11 before it was released. You needed to take responsibility for it. Unless the developer decides to update the app, or provide a method to extract the data, it is lost. There have been some reports of backup extraction software working on some computers. You would have to search for that. If you read the fine print for the App Store, and iTunes, you will see that Apple has no responsibility for any content that is removed from the store for any reason. Content can become unavailable at any time. Lesson learned.