At this very moment : Facebook, WooCommerce, OpenCart, PrestaShop, Shopify, Shoplo and some Saas integrations important mostly in Poland, like : IaI, Shoper etc
We have API (working and well documented). And very big companies usually integrate with us this way.

In our road map for this year, we have to add webhooks and zappier for sure. Time for delivering other integrations that you asked for would depend on the importance of customers' needs.