Third party add ons can really expand the number of front end and back end functions at little or no extra cost. They work by adding some code to your website and to function you'll need to register and open an account with the provider,
here are some popular add ons...
Google Analytics is a service offered by Google that generates detailed statistics about a website's traffic and traffic sources and measures conversions and sales. It's the most widely used website statistics service. The basic service is free of charge and a premium version is available for a fee.
Their social media share buttons are used all over the web and on the back end you have access to some analytics about your website visitors. If you have any social media pages they provide follow us buttons too. Other features include marketing tools and popular content newsfeeds.
If you have an active facebook page then it's worth adding facebook's social plugins on to your website, on the backend there are analytics to view visitor activity. As well as the usual share buttons there are embed codes for videos, posts and comments can be made from and about your webpage.
MailChimp makes it easy to send professional email newsletters within the law, manage your subscribers, track campaigns and integrate your email sign up form with your website and social networks.