Debug existing ipad application

We have an existing iPad application that allows our users to capture textual and photographic information. The app has been released for over 12 months but our users are now experiencing a number of bugs during capturing data and synchronisation of data. The application makes use of a wizard type form and during input it will sometimes crash back to the iPad home screen and the user will lose their work. Sometimes on submitting the form to the database the application will crash and again data is lost. the applications works by first the user logging into the application with their credentials, then downloading information from a database that is stored on Amazon AWS restricted to user based on their access rights. This information will be stored on the iPad. This ties into the synchronisation feature that we have. The app should not upload duplicate information from a users iPad, we need this to be fixed also. Depending on the users connectivity to the internet the user can either save their information onto the iPad as draft and when connected to the internet they will submit whatever they have saved to the AWS database. It's mostly at saving the draft or submitting to the AWS cloud where it is crashing. obviously there is more to this but this is the crux of the issues we are experiencing.