Hello. Firefox has useful feature. When you watch video on Youtube you can tap Open in app and the same video will open in installed Youtube app. This also works for Facebook, Twitter, some news sites, and so on: you tap Open in app and same post is opening in app. But this menu item is missing for some sites I need. For example for vk.com(social network). I have an installed vk.com app on my phone, but when I browse a post on vk.com using FF there is no Open in app item in menu, so if I want to read the post in app I have manually find it which is very inconvenient. Could you give an idea why and how to fix it? Is there a list of sites where Open in app feature works? My question is about opening link in FF only. There is no problem with opening in apps when clicking inside some other apps, not browsers. For example when I click link on facebook post inside twitter app it opens in facebook app, or needed browser, or ask where to open in compliance with settings of my android phone. So that's ok. But those settings don't work for links in any browsers.