There are a few ways to do that. In any of them, you'll have to create whatever CSS you want to style it.
1. Open the qa-theme/<your-theme>/qa-theme.php file
2. Add (or merge, if it already exists) the initialize() function:
public function initialize() {
parent::initialize();
if (qa_is_logged_in() && isset($this->content['navigation']['user'])) {
$this->content['navigation']['user'] = array(
'google_search' => array(
'url' => 'https://www.google.com?q=' . urlencode(qa_get_logged_in_handle()),
'label' => 'Google your name!',
),
) + $this->content['navigation']['user'];
}
}
3. Edit the url and label values in any way you want
4. Use a text that represents whatever you're adding instead of google_search
5. Add this to qa-theme/<your-theme>/qa-styles.css
.qa-nav-user-google_search:before {
content: '\e812';
font-family: "fontello";
display: inline-block;
width: 1em;
background-color: #2c3e50;
padding: 5px;
margin: 0 10px 0 0;
text-align: center;
line-height: normal;
border-radius: 1em;
}
Note the pattern to follow regarding google_search.
This is a bit SnowFlat oriented. You can change the icon by changing the content of \e812. SnowFlat includes icons ranging from 800 to 825. At the bottom of the qa-styles.css file you'll find a reference of what each icon contains. If you want more images, you'll have to import your own font, but I believe that's a completely different question.