The best place to start if you need help with a specific product is to contact the developer. All WHMCS Marketplace developers have both a website and support URL listed.
Favicon manager module lets you add a favicon image to your WHMCS website.
Social Login is a free WHMCS plugin that allows your visitors to comment, login and register with 40+ social networks like for example Twitter, Facebook, LinkedIn, Instagram, Google and Yahoo.
Display social buttons to allow your customer sharing your website products and pages to Facebook, Twitter, Pinterest, LinkedIn, Reddit, etc
Sticky, or fixed, navigation is basically a website menu that is locked into place so that it does not disappear when the user scrolls down the page