Facebook have changed the app.facebook.com behavior!
 I am so used that Facebook changes stuff that I don’t like, so I was like 99% sure that this was here to stay. But it wasn’t, the apps are opening up as before again, so this FIX isn’t needed. But if you need some nerd tips, scroll down to learn 3 different ways to open up links in a new tab by YOUR CHOICE! =)
Ish, I have a lot of tabs open as is, without Facebook forcing me to open up apps (Bubble Witch Saga, Farm heroes Saga, Candy Crush Saga, Pet Rescue Saga etc..) in new tabs. FACEBOOK IS RUDE and apparently insecure as well, since they seem to believe that we don’t come back to the main site from the apps. Pfft!
I learned to live with the fact that external links leading away from Facebook opens up in a new tab, I have even implemented that very similar behaviour here at my website! But when the apps want new tabs I have to do something about it.
I found this handy little plugin for Chrome that makes Chrome ignore the code Facebook (and this blog) is using to force new tabs on you.
After installing the Chrome Plugin “Death to _blank” I now have all links at all websites opening up in the same window/tab where I currently read.
That meaning whenever I want to use a new tab I use my scroll wheel at the mouse to open up a link in a new tab instead of the left hand button. You can also use the key CTRL while left clicking a link to open up the link in a new tab or right click the link and choose what to do from the options opening up.