Remote Control non Tech-savvy family members phones

My mom (and several other family members) are not very tech-savvy and most of the time I can walk them through whatever challenges they are experiencing. However, on occasion when I am short on time or lets be honest patience, it’s just easier to remotely connect to their device and do it myself. The problem I have is when she needs help on the computer we use TeamViewer flawlessly but I am not having any luck with it on our Apple phones. Just wondering if there is another app out there that will essentially do the same thing TeamViewer does for us on the Mac computers but only on our phones.

Any suggestions?! Thanks in advance!