For those unfamiliar With Two-Factor Authentication, it is an opt-in system that's designed to increase the security of Apple ID accounts. It asks users to provide a verified code when signing in to new devices, when using iCloud, and when using services like iMessage and FaceTime.
Apple's iTunes Remote app was last updated in September of 2016, adding iOS 10 compatibility and mi**r performance and stability improvements. The app lets users browse their iTunes libraries and send music to AirPlay speakers.