Q:

Progressive Web App in Chrome Custom Tab

I am building a Progressive Web App. When I open it in the Chrome browser, I correctly see the "add to home screen" option come up in a bottom sheet. However, when I open my app in a Chrome Custom tab, the "add to home screen" bottom sheet is not appearing.
Does anyone know if Chrome Custom tabs supports the Progressive Web Apps manifest?
Update: I've filed a bug against Chromium for this issue https://bugs.chromium.org/p/chromium/issues/detail?id=731171#c2

A:

Chrome Custom Tabs has the ability to show an "Add to Homescreen" menu item, at least in recent builds of Chrome.
I can confirm that manually selecting the "Add to Homescreen" menu item will make use of the web app manifest data when creating the homescreen item.
However, I don't believe that the logic for automatically triggering the Web App Install Banner is enabled for page views with Chrome Custom Tab at this time—I experimented a bit and never got the banner to appear, at least.

