Regarding using favicons on your site you can create favicons with different dimensions for different mobile devices - iPhone, Apple, Samsung Galaxy, tablets:
- 32 X 32 is for Retina displays
- 144 × 144 - big iPhone и iPad displays
- 72 × 72 - iPad (old ones)
- 57 × 57 - Android
You can add them in your header.php RIGHT AFTER THE HEAD tag - the opening one! You can use Notepad++ and save it with UTF-8 without BOM; Please look at this code which you need to put:
<!-- Favicon for Desctops -->
<link rel="shortcut icon"type="image/x-icon"href="favicon.ico" />
<!-- For third-generation iPad with high-resolution Retina display: -->
<link rel="apple-touch-icon-precomposed"sizes="144x144"href="apple-touch-icon-144x144-precomposed.png">
<!-- For iPhone with high-resolution Retina display: -->
<link rel="apple-touch-icon-precomposed"sizes="114x114"href="apple-touch-icon-114x114-precomposed.png">
<!-- For first- and second-generation iPad: -->
<link rel="apple-touch-icon-precomposed"sizes="72x72"href="apple-touch-icon-72x72-precomposed.png">
<!-- For non-Retina iPhone, iPod Touch, and Android 2.1+ devices: -->
<link rel="apple-touch-icon-precomposed"href="apple-touch- icon-precomposed.png">