After a few month without working on it, I've decided to finish my manager. It is now "usable". It is written in Python using wxPython. I use the ComicVine API to obtain the informations.
Basicaly, you can add/remove comics in your collection by either searching for a new volume or selecting an already known volume.
It is full of bugs, some features are not implemented, but that's a first step.
I haven't added License informations to the files, but if some of you are interested to take a look at it, I can send you the files.