in Podfile you can run some code w/ post_install like :

post_install do |installer_representation|

      puts "Removing some items"

      Dir.chdir("some path") do

          `rm some file.txt`

      end

      puts "Removed !"

end

To disable greyed tab bar icon and text in swift you can just do

self.tabBar.items?.forEach({ (item) -> () in
item.image = item.image?.imageWithRenderingMode(.AlwaysOriginal)
})
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : UIColor.blackColor()], forState: UIControlState.Normal)