I would like to use My Movies for iPhone, iPad, Android, Windows Phone or Mac OS X, but why is a user account required?
The reason for the requirement of a user account is that the application although functioning as a standalone product is also part of a product suite, where your movie collection can be shared between multiple application.
To be able to give you easy access to the same movie collection both from multiple clients and other products in our suite, your movie collection is stored both on your device or devices, as well as on our online servers as references to the title profiles on our service. This approch does not mean that you are required to be always online with your phone to use the software - the data is also stored locally on the device, and operates well, even when you are not online.
This shared collection means that you at any time can install any of the other applications in the My Movies product suite, and be able to manage your collection from these, even though you added your titles from a different client.
The overall benefit of having a user account, and having your movie collection stored for this account, rather than on individual devices only is that you will have access to the same unified movie collection from multiple devices and products at the same time, without ever having to consider data imports, exports or backups.