Really, it makes the work with extensions in general not simple ;)
I started with the Ohanah extension and I just liked the backend. Of course, you have to read a lot about module injections to understand it but after it works great. The backend view is really professional!
I had some trouble to understand how I can change the styles for the frontend like a list and others but finally it works. Thanks a lot to the support from Ohanah! They are very profession and patient ;)!