This is a very welcome addition to the family of 2-step verification apps and web services. Apple has just enabled 2-step verification for iTunes and iCloud accounts (for most people, this is the same account). Two-step verification requires you to have an already-approved device with you at all times when signing into Apple services to change profile information or to make purchases. It’s an extra step in a usual process but one that is highly recommended from all security personnel. Activate it in your Apple ID preferences now.