In order to customize buttons as well as the share counts from different social networks and url sharing services, you can use a proxy server. The social button server Meddelare does exactly this (FYI, I'm the developer behind Meddelare).
Meddelare: This is an open source and self-hosted alternative to sharing services such as AddThis and ShareThis. Because you run the proxy server yourself, you are also defending your users’ privacy against the social networks’ tracking. Users only opt in to their tracking once they decide to click a share button – never implicitly just because they visited your page.
There are several versions: a standalone server, middleware for your Express.js server and a separate backend for completely custom solutions.
See Meddelare's examples for the JSON/JSONP you get from the server plus script usage.
