Waiting for answers

Its working perfectly fine if you are using latest Firefox version 34. As once you tap a link that has "Open in App..." such as Twitter, YouTube, Instagram, it managed to automatically redirect you to the app.

• • If the apps you already install on your phone, whenever you tap the link that has "Open in app.." it will automatically redirect you to the apps.

Else, if you did not install yet the app on your phone, it will usually will ask you to continue using the browser or to "Switch to the app" which it will redirect you to the Apps store, then you can install it.

I have all apps installed and last version of Firefox When I click on Open app, it opens Appstore page for thar app even though it is already installed

Ok I solved it, I had to open the link in Safari and then open the app from there. Thrn go back to Firefox and try the same link and it will open the App now instead of Appstore

Thank you for letting me know about it, glad to hear it is working now.