I have checked the application and it doesn't offer anything related to recovery. If you still have it installed on your iPad, then I recommend checkings its About menu in the Settings. You should have a website and contact methods in case something goes bad. Use the available contact options to get in touch with the developer. Most of the developers implemented secret ways to recover the files, but you won't have access to them until a contact has been reached. Avoid installing another application or re-installing this app as you'll probably lose the pictures.