Did you try adding the web app as an instant app on your home screen? Just a workaround if you can't find it at all.

Try making an account on Mobilism and requesting it there.

Wow, it's almost twice as much on iOS! That's nuts.

As long as the site is running, someone could just make a web wrapper and offer it for free. The site owner shouldn't see it as anything more than just web traffic.

Or you could browse to it using your browser of choice, sharing it, and saving it to your home screen. That works on iPhone/iOS and I'm pretty sure Android can do it, too, though I haven't tried. (I have an Android phone but I don't do much on it. I've made "web shortcuts" to IMDb because their mobile site is trash with too many ads, and to TMDB because they straight up do not have an app. And Wikipedia because their app is hot garbage.

Anyway, on Android, browse to the web app, share it, and see if you can put it on the home screen somehow. I'm sure you can. I'm sure if it were an iOS exclusive feature, I would know that for sure, since I generally follow mobile tech.

I've emailed the developer to inquire about buying and gifting it to you. I don't think Play Store has a way to gift apps natively, especially between countries.

Can you DM me your Play Store email? Doesn't help because of the cross-country issue.