When visiting a link to a Hardcover entry on mobile it by default opens the webpage, but there is no option to open it in the app. See: https://developer.android.com/training/app-links/create-deeplinks

Example: Firefox for Android has a menu option called "Open in app". Tapping it opens the corresponding page in the associated app. If I tap a youtube video link, it asks me if I want to open it in the browser or redirect it to the app. I haven't used Chrome in a while, but I think they open a dialog box asking the same question.