Lots of people now have only phones and that should be considered. But it's also important that buyers of a product know if they're going to need a specific non-supplied part to make it work, and that issue is on the buyer to find out. For instance the old Mobius, which initially required a windows PC to access it's full functionality but could also be used without that. You also have to supply your own PS and mount for that cam., but there is a phone app for it now
All this info can easily be found so persons considering a Mobius who look at any depth will know all these things before buying.
As I see it,
the big issue in going to phone apps compatibility in that Android has so many variations that it's nearly impossible to make a complex (or even a basic) app work with all of them, and there's IOS apps to be built as well. My old phone could hardly run anything. My new phone is better but in a year or two will not be given consideration of app developers because of it's design age
Especially Andriod needs to settle on and require one specific way to build phones and tablets so that one app will work for all of them from that point onward, but nobody's doing that, and one can't fault a cam manufacturer for Android's failings.
I do understand the OP's pain and disappointment as I've suffered from inaccessibility too, only in a different way. Especially when I was told by a cam manufacturer that a tablet I went out and purchased based on their reccomendation would work with their app but it didn't
The Android version number was fine, but the exact variation I had wasn't
I had no other need for the tablet so my money was essentially wasted
tldr:
All I can suggest to the OP is that they ask around- some friend or family member or co-worker will have a PC and can load the files for you. It's not optimum but it works, and you're out nothing in costs doing this.
Phil