Is there an algorithm that counts Joback groups in a structure? So I was wondering, there are a lot of cheminformatics tools (eg Babel) out there, to analyze and convert representations. I also saw some codes which counts certain groups, but ignores the carbon chain, which is obviously not suited for a Joback script. My google research only turned me a "homemade" matlab code found at Reddit, but it is no way general, as the first step of it is to exclude most of the rings.

So is there any open cheminformatic tool for this problem?
So it looks like 'Jobeck groups' are some set of functional groups that you want to find in molecules.

Sounds a lot like substructure search, for which there are many cheminformatics tools (like SMSD, for example) however, since you mention OpenBabel:

http://open-babel.readthedocs.org/en/latest/WritePlugins/AddNewDescriptor.html

talks specifically about 'group contribution methods' and gives a simple example of how to get the counts for a set of functional groups.