[aescrypt] AESCrypt operational vulnerability iOS

iOS devices: For security, the default for AEScrypt pro APP should be that decrypted files are purged on APP closing; unless a switch is positively selected to preserve them. Can this feature be added - Because:

It is a troubling vulnerability to not delete decrypted files from the APP when it is closed. Anyone with access to the iOS device potentially can reopen the APP and see unprotected files. Requiring or depending on the user to positively delete unencrypted files from the APP as the default action, operationally is hostile to security.