Security of information
The information that you input is password protected and is stored on the device only, and does not go to a server, thereby avoiding the problem of information being hacked at a server level. If you are concerned about losing your device, you can simply back-up the information stored on the App on a cloud service. You then have the best of both worlds, having information confined to your device but with a back-up option on a cloud.
Below is a link to information from Apple about its iCloud service
Another benefit of the information being stored on the device is that information can be retrieved from the App even when you do not have Wi-Fi service.