Thanks, Axel,
your sample looks cool!
And thanks for sharing. 
I guess, I do something wrong, because ubacher could let it run.
I cannot enter a category-field.
Your app runs fine, the tree to choose a category opens and I can click on a category, but it does not appear (like the output-folder).
Then I thought, ok, the category is maybe choosen, but simply hidden in the field.
But after clicking on the green button to generate the gallery, I get some infos, but nothing happens further.
Also the output - folder is empty, hence I cancelled the app.
For testing I have only some files in the categories, about 10 or so (jpgs).
THANKS for the excellent manual, cool!
What I wonder is, what is this comment about "not for online"?
If the gallery once online, would I am able to copy the whole stuff on my handy and let it run there (not online)?
And the last question:
For creating the thumbs and jpgs ... could we do this not using, after closing your app, the batch-converter from IMatch?
I attaches some screenshots, but I am sure, I do something wrong.
