I have some little problems.
A) When I open the app from the launcher: I click a link to an external page from facebook news feed, it opens a blank page and then my browser app (I deselected Settings->Performances->"Open links inside the app").
If I open, for example, a facebook event link from whatsapp, I don't have this problem (it seems another fast ui, if I click on the gear I have some different settings "Open links inside the app").
B) Another problem is that if I see a photo in full size from a friend, then I can go back (with my back button) only to the photos page, and not to the news feed.
1) news feed
3) photo of a friend
4) full size of photo
5) go back to (3)
and then I can't go back to page (2).
If I open, for example, a facebook event link from whatsapp, I don't have this problem.