RepairCal

RepairCal is an internal utility used by Apple and other Apple Authorized Service Providers (AASPs) to calibrate the display units and batteries of new iPhones, as well as recalibrating displays and batteries of newly repaired iPhones. It flashes Horizon Firmware to the device, which is responsible for helping to recalibrate the screen and battery. RepairCal is not to be confused with DisplayCal or 3DTouchCal. It is installed through 2 or more PKGs, one of them being the PKG to install the apps and all of its components to the Mac, and the rest being the Horizon Firmwares, one of which is the firmware for the current iOS version, and the others being named SupportSoftware, which contain older iOS versions of the firmware.

The startup screen of RepairCal makes reference to searching GSX (Global Service Exchange) for "RepairCal Procedure" to find iPhone screen calibration instructions. The URL for GSX is gsx.apple.com, however you cannot sign in with a standard Apple ID.

Wallpaper
When installed, RepairCal adds new wallpapers to your system. Two different wallpapers are installed, however the first is localized to 16 languages while the second is only in English. The file names are as follows:,   and. Interestingly,  is included even though   is already in English.

A LaunchAgent called  is installed to   and is used to run   at login. This Python script sets the desktop wallpaper to the correct version for your Mac's current language. This runs at login rather than once during install to make sure it is always present.

The text on the English version of the wallpaper says "For any issues with iPhone Display Repairs, please chat with ACS using a different computer." ACS here refers to Apple Channel Support, which can be used to request support for issues regarding the software. See both variations of this wallpaper in Gallery. ACS can be accessed by going to acs.apple.com, and interestingly it can be accessed with a standard Apple ID, unlike GSX.