eqagunn's Issuu Publication Downloader, slightly modified from http://eqagunn.blogspot.com to zero-pad the file name. Instead of
file1.jpg
file2.jpg
file3.jpg
...
file10.jpg
You'll get
file0001.jpg
file0002.jpg
file0003.jpg
...
file0010.jpg
So that the file list sorts by page order, making PDF creation easier.