First of all i have downloaded the Facebook app form app store and logged in there and then i downloaded the Hackbbok form this url https://github.com/facebook/facebook-ios-sdk and installed into my phone through xcode.
When Hackbook application is launched it shows "Login with Facebook" button. When i click on that button it opens the facebook app which i downloaded form app store and then re launches Hackbook. But Hackbook still asks for login.
But when i uninstall facebook app which i downloaded from app store then it works fine as browser is launched when i click on the login button
Similarly i have another app which imports contacts from Facebook when i download facebook app from app store and login there then my app doesn't import contacts and shows blank screen and when i uninstall the facebbok app then it starts working again.
Both apps works fine if Facebook app is not installed.
Any help regarding to this issue will be really appreciated.