I have installed the plugin and almost everything works fine. Thanks a lot!
There is just on exception: I'm using it to share to a FB page - text, link etc. works well. But the image that gets exported seems to be picked randomly. In one case it was the Featured Image ("Artikelbild" in German) as I would have expected. I other cases it was the second or third image (although both blog posts also have Featured Images).
You can see the Featured Images on dreiminutenei.de (the "Lammkeule" and the "Gemüseeintopf" and compare to the images on http://www.facebook.com/Dreiminutenei.
Thanks for your help - since I'm writing a foodblog, images are really important.