Iphone App For Beeper/Pager?

My father is Psychologist and recently got his first iPhone.

He still uses a Beeper/Pager for when his *patients* have an emergency.

He is in private practice and does not have other partners who are on call, nor a dedicated answering service. So when patients call his office number, they are directed to call his beeper number if they absolutely must speak with him immediately.

Of course, having this is expensive, and I would really think that there would be an iPhone app he can use to replace this beeper.

Now there are several beeper/pager apps available, but what I keep finding is that they are for *doctors* to contact each other during an emergency. I can't find any for *patients* needing to contact the doctor directly.

If there was an app that had a numeric message feature, that will make the phone loudly go off, when a different number is dialed, that would be perfect.

I've looked into burner number apps, but none of them really seem to fit, because they are all Wi-Fi based, and it would simulate a phone rather than a beeper. Thus, patients would be potentially leaving messages on a phone that is neither secure nor reliable.

Is there a solution for replacing the beeper/pager for patients in an emergency?

Why am I seeing a COMPLETELY different person on camera than I see in the mirror?

I've realized that in the mirror I look so sexy, like 8/10, but when I take my iPhone X camera (not bragging just saying what camera) and take a selfie even at 10 feet away I look HORRIBLE, like my jaw is crooked a little, lips are not symmetrical at ALL! My eyes are two different sizes and last but the worst one my skin looks red and shows all my little red spots. I don't what to trust, my eyes in the mirror or the camera. I cried today cuz I couldn't figure out. Please help, should I trust the camera or the mirror?

How much does a phone battery degrade if kept in storage?

If you buy a brand new, unopened phone that has been in storage and released 2 years ago, approximately how much of the battery has already degraded? Does this vary with different types of smartphones like iphones or androids?

What is the easiest way to get photos from a DSLR camera to an iPhone?

I've been taking pictures for a little bit now but I'm super cheap! I don't do it professionally, mainly just as a hobby so it hasn't been a crazy big deal but I've been getting more into it and can't get any of my pictures! I've tried using a USB to iPhone type adapter and dropbox and email and google photos and outlook onedrive and my computer, nothing will load it or go through, usually only 1 or 2 pictures! Have lots of videos too.

IPhone connected to AirPlay but no Apple TV?

My iPhone 6 is connected to AirPlay, and whenever I try to watch a video on my camera roll it says "Airplay; This video is playing on Apple TV." I don't have an Apple TV. We did very recently install Foxtel Go which connects to the Wi-Fi, but it even happened at someone else's house where I didn't have any Wi-Fi. I've tried turning off Wi-Fi, turning off bluetooth, anything I can think of. This never happened before we got the TV installed. I want to be able to watch videos.

Added (1). Update: I even tried turning off bluetooth. I can still hear the audio but can't see the video.