I\'ve recently discovered the awesome iOS5 custom Settings URL Scheme, which can be explained in detail at this great website.
I\'ve found this to work, dir
As of iOS10 you can use
UIApplication.sharedApplication().openURL(NSURL(string:"App-Prefs:root")!)
to open general settings.
also you can add known urls(you can see them in the most upvoted answer) to it to open specific settings. For example the below one opens touchID and passcode.
UIApplication.sharedApplication().openURL(NSURL(string:"App-Prefs:root=TOUCHID_PASSCODE")!)