You need to add:
UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
And change:
self.toolBar.items = [[NSArray alloc] initWithObjects: flexSpace, self.barButtonDone,nil];
I thing that you can:
//self.navigationItem.rightBarButtonItem = self.barButtonDone;
Information:
UIBarButtonSystemItemFlexibleSpace
is a blank space to add between other items. The space is distributed equally between the other items. Other item properties are ignored when this value is set.
Apple documentation: UIBarButtonItem Class Reference
Also, you have the Flexible Space Bar Button Item
in Xcode Interface Builder: