I released a server rendered progressive web app recently and everything works great so far. However, Android using chrome shows a banner to download the app which is awesome, but it doesn't on iOS. Using Safari, a user needs a few clicks to get to the "Add to homescreen" feature which is bad.
So here I am, I'm satisfied with my PWA, but I would really love to be able to tell the user myself that this app can be added to homescreen.
As far as I can remember, I saw https://marvelapp.com/ doing it to add a prototype to the homescreen.
iOS - Safari currently don't support Web app install banner, like in Android - Chrome.
There is no way to programatically trigger install banner in Android as well, except for the case when you catch the beforeInstallPromot and use that to show the banner.
In the linked answer, you can check on the alternate option on how to show in app banner to guide user to add to home screen. Here is some code example for the same, which is iOS specific(look under #PROTIP 3).
Here is the way it can be done
来源：https://stackoverflow.com/questions/51160348/pwa-how-to-programmatically-trigger-add-to-homescreen-on-ios-safari