Mobile devices with a minimum of 2 GB RAM are recommended for running ArcGIS Indoors. All current iPhone models meet this requirement.
Indoors uses data from different sensors on the mobile device, including GPS, Wi-Fi, and Bluetooth radios, to determine indoor position. These sensors differ from device to device, so you may experience different precision of indoor position at a given location.
iPhone 6s devices and later are supported.
iOS 10.3 and later are supported (iOS 12 is recommended).