Need something achievable for an extremely tech illiterate person on iOS. I got told about this after they are already gone and have no access to the device, but am asked to solve the problem.
EDIT: (SOLVED) Signal was super easy, works awesome, and was easy even for my mom to figure out on her own. Thanks
Probably ‘Google Play [Services]’.
OP doesn’t have access to the phone(s) to install & setup something for them.