how to add vk.com?

There are lots of social networks that are not present in the social counter. At the moment these are the only options. We will try to improve it with the next future updates.
Thank you!

Unfortunately we have no answer for this as the development team will decide what gets implemented and what doesn’t. But as VK.com is not that popular, I’m assuming it won’t make into the social counter too early as there are lots of popular social networks that are not present in our social counter and they are way more popular than vk like for example: http://www.statista.com/statistics/272014/global-social-networks-ranked-by-number-of-users/
I will add VK.com to our list but I cannot promise anything. Until then you can maybe use a plugin to have a VK social widget on your site.
Thanks.