Hi mikounet,
Plugins supported on 2.x are all published but facebook plugin ( cars, real state, dating, products, jobs attributes, extra feeds, breadcrumbs, google maps, google analytics, time elapsed and ads for osclass).
I spent two days traying to work out Facebook plugin, then I gave up. There's no PHP documentation for Facebook, official documentation send you to an error page, non-official documentation is quite old and not compatible with the official PHP library. So you're left with an official library with lots of errors (there a few people who already fix some parts, but for some reason they didn't include the patch yet on the official library), no documentation,... I tried different approach (one was to copy a WP plugin). I'm pretty close to make it, but I was reaaaally tired of that and I also has more relevant tasks to do, So probably by the end of the week I'll give it another shot and hopefully release the plugin