Safari 26 brings a smoother, app-like experience to many websites on iPhone and...

https://xeon-wiki.win/index.php/When_Did_Safari_Start_Supporting_Web_Application_Manifests%3F

Safari 26 brings a smoother, app-like experience to many websites on iPhone and iPad. When you add a site to your Home Screen, it can now open without the usual Safari interface, thanks to the new 'Open as Web App' option