Question Web App Icon on Homescreen won't refresh!

Hi guys,

I am developing a homepage for my school's video project (videowerden.de)and I wanted to integrate support for Homescreen Web App Icons on iOS and Android.

I have already managed to have our custom icon displayed when you add our website to homescreen on a mobile phone or tablet (via Chrome browser), but now I have changed the icon (I was not satisfied with the first version) and the changes won't apply!

Everytime I delete the Web App icon from Homescreen and try to set it up again, the old icon reappears! It seems to be cached somewhere on my device (HTC One)

Clearing my Chrome's chache or restarting the phone won't help, what can I do?!?

Here's the code I used in my website's head.html:

HTML Code:
		<!-- iOS and Android Homescreen Icons -->
		<link rel="shortcut icon" sizes="196x196" href="icon-196x196.png">
		<link rel="apple-touch-icon" href="apple-touch-icon.png" />
		<link rel="apple-touch-icon-precomposed"  href="apple-touch-icon.png" />
Icons are stored in website's root directory.

ANY IDEAS?!