Since Apple changed the security settings in iOS 8.3 that prevents file managers and transfer utilities such as iFunBox, iTools, iExplorer, iBackupBot, PhoneView, etc. from gaining access to app directories on an iPhone, iPad or iPod touch. Fortunately theres a workaround and unlock App Sandbox and you can save your hacked Documents, files, and Library folders to your Apps. There are so many methods on how to access your Apps Sanbox. This is one of the easiest method:
REQUIREMENTS:
-Safari
-iFunbox, or any file manager
INSTRUCTIONS:
1. Open Safari on your iDevice and go to http://www.vshare.com/. Then press Download (unjailbroken) and install it. After it was installed, open vShare and it will prompt you about warning "Untrusted App Developer", just press Trust. Any apps you downloaded on Apple App store will be locked if you are in iOS 8.3.
2. Now that vShare is installed and running, go to Search tab and search any apps you want to save your hacked Savegames. Press Install. After you pressed install go to Downloads tab and wait for your app to download. When the App is finished downloading vShare will prompt you to install the app automatically (you can configure not to install apps automatically on the Settings tab). Press Install, don't press Cancel cuz the downloaded app will be lost and you have to reinstall vShare again (its a bug).
3. Now that the cracked app has been installed, its either you open it first or not. Open iFunbox or any file manager and copy/paste or drag & drop your hacked files to your app directory.
4. I don't recommend you to download cracked apps on third party programs, but if you are frustrated since Apple blocked access of the entire sandbox directory of every installed App beginning on iOS 8.3, this is the easiest method to gain access on your locked Apps. There are so many methods like backing up your Apps and data through iTunes or iTools then open the backed up apps using a zip file to replace the Documents file by turning off Hide extensions for known file types on Folder Options then reinstall it again on your iDevice bla bla bla......well good luck!
*If this method helped you and brought tears to your eyes, press the Vote or Thanks or any buttons down there. Have a nice day!
Also, check this tutorial: http://iosgods.com/topic/9650-tutorial-how-to-apply-save-game-hacks-on-non-jailbroken-ios-8384-and-higher/