Table 1.

Use cases and characteristics of each protocol version.

Characteristic	Version 1.0	Version 2.0	Version 3.0
Use case	Exploratory testing of platform capabilities	Small-scale study	Study requiring scalability
Interactive time	30-60 minutes Lowest level of automation	20-30 minutes	5-10 minutes Highest level of automation
Requirements	Minimum financial investment Study team Apple ID for each phone Participants must have home Wi-Fi USB connection required to reset PIN-locked phone	In addition to previous requirements: Apple Mac computer running Apple Configurator software Low-cost SIMs without cellular service	Apple Mac computer running Apple Configurator software Apple Business Manager (free) Mobile Device Management (subscription fee) Cellular plan for each loaner phone
Features	Unrestricted Apple App Store Activation Lock to prevent circumventing security measures by factory reset Find My iPhone GPS tracking to reduce the risk of theft iOS restrictions to disable iCloud and prevent inadvertent sharing of PHIa	Increased consistency in configuration due to automation	Apple Device Enrollment Program to prevent circumventing security measures by factory reset Lost Mode GPS tracking to reduce the risk of theft Mobile Device Management policies to disable iCloud and prevent inadvertent sharing of PHI
Limitations	Manual (error-prone) configuration of all features and app installation Insertion and removal of SIM card required to activate phones after each reset Find My iPhone not helpful outside of Wi-Fi range	Manual configuration of Apple ID and app installation Find My iPhone not helpful outside of Wi-Fi range Apple Configurator unable to share configuration profiles with other computers—single team member performs all setup	Apple Configurator required for first-time configuration of each loaner phone

^aPHI: protected health information.