I've just downloaded it from your link and this is how I've got it working. The downloaded file unzips to a folder called SimpleViewer_v17. Inside this folder are two subfolders called images and thumbs. I made copies of 13 of my pictures to keep the originals safe and then resized the copies to 480x360 pixels for landscape shots or 360x480 for portrait layout and saved them as standard jpegs in the images folder. Then I resized for thumbnails to 60x45 pixels (45x60 for portrait) and saved these as standard jpegs in the thumbs folder with the same filenames. Back in the SimpleViewer_v17 folder I opened imageData.xml in Notepad and changed the default image filename of 115-1503_IMG.jpg between the <NAME></NAME> tags to correspond with the 13 different names of my images. Double-clicked index.html and it worked first time. In the imageData.xml file you can duplicate a section starting with <IMAGE> and ending with </IMAGE> to add extra pictures (adding your own picture's filename) or delete any that may be unused and can also change the Captions.
I haven't uploaded to the web but if you stick to the folder structure there shouldn't be any problem. Hope this helps in some way.