It looks like I cannot show more than two molecules on one page. Here is the third one I wanted to show (you may have to click the header of this post to see it):
For molecules that are not in their data base I can enter the molecule as InChI (which I can create through open babel).
This is the molecule of my Master's thesis [2,2'-bipyridyl]-3,3'-diol with the InChI 'InChI=1/C10H8N2O2/c13-7-3-1-5-11-9(7)10-8(14)4-2-6-12-10/h1-6,13-14H'.
[To correctly translate it into a form that the browser interprets correctly, I can convert it on their homepage (I enter the InChI and take the converted one from the link it produces). Then it looks like this: 'InChI%3D1/C10H8N2O2/c13-7-3-1-5-11-9%287%2910-8%2814%294-2-6-12-10/h1-6%2C13-14H']
[Edit:] The problem was that I did not put the 'InChI=' prefix and it is not necessary to do this conversion.
In fact the molecule should be all in one plane and have intramolecular hydrogen bonds but it is still cool that the tool can create the structure from just one line.