Yep, some sites, like PeakD's release and beta sites, allow the creation of web apps via browsers. I use Vivaldi, and it's a quick process. Exactly how to do it may be a little different for you since you're on an iPhone, but usually once you're on a webpage that you want, just click on the main browser menu, and choose 'add to homescreen', and it will give you to create either web app or a shortcut. 'Install' is what to choose for the web app.

Indeed, Keychain seriously annoys me sometimes with some of the stuff, live the for forever-refreshing webpages. 😁 🙏 💚 ✨ 🤙

!DIY
!INDEED
!STRIDE
!WEIRD