JE-Comics is a Java application able to convert a group of images into a pdf.
It can take as a input Jpeg, gif and png files even if compressed in a zip o cbz file.
Useful for making an e-book friendly version of comics, or just easily convert the scan of documents and notes into pdf.
It has Built in support for some e-book readers (like Iliad and sony prs), and some image optimization filters for enhancing the quality of the resulting pdf.