Apple has just released iOS 7.1, it's more stable, more beautiful, more "the most advanced operating system". But with all that, there is a great improvement for web developpers, particulary for mobile web developers that we are all, of course.
They added the possibility to minimize Safari UI without hacking with some 1px move or some ugly things. Now to minimize UI, you have just to add "minimal-ui" in the "viewport" meta tag.
<meta name="viewport" content="minimal-ui">
It's easy and it's very nice, when people will visit your site, the UI will be reduced to a very small title bar.
I Hope that Google will follow the same specification on Android.