Update: please check out this up-to-date Apple support article on how to Turn off Find My on your devices and items. When you bring your iOS device to our shop, we ask you to erase it and turn of Find My iPhone (FMi) feature. It is because sometimes the repair concludes by swapping for a new or refurbished device. The best is to back up the device (using iCloud Backup, or a computer with iTunes), then turn off FMi with Settings > iCloud > Find My iPhone and the erase the whole device in Settings > General > Reset > Erase All Content and Settings....