Pexvia isn't on the App Store yet — but you can install it as a full app in under a minute, right from Safari.
This only works in Safari — Chrome and other browsers on iOS can't install web apps. Go to app.pexvia.com.
It's the square icon with an arrow pointing up, in the toolbar.
Scroll down the share sheet if you don't see it right away.
Pexvia now sits on your Home Screen like a native app — full screen, no browser bar.