Safari 26 changes how websites work on iPhone and iPad by making many of them...

https://spark-wiki.win/index.php/How_Do_I_Turn_Off_Open_as_Web_App_in_Safari%3F

Safari 26 changes how websites work on iPhone and iPad by making many of them feel like apps. When you add a site to your Home Screen, it now opens as a web app—no browser bars or tabs, just the site itself