XPDF: Photo to PDF Converter is an application designed to convert images into PDF files. Also, the utility is meant to work the other way round, meaning that it will let you save PDF documents as image files. It supports the most common image formats, including PNG, JPG, TIFF, BMP, EMF, ICO, and WMF.
The tool seems to be easy to use. Once you open it, you can drop your files directly into the main window or browse for them from within the app. The list of loaded files is displayed instantly, giving you information related to the name, the format, and the size of each file. If you have good eyesight, you may perceive a rectangular button placed above the list of imported files. This button is meant to help you load new items. However, the explanatory text displayed on it is so faded that its functionality may remain unnoticed.
There aren't any conversion options. You can't merge multiple files into a single PDF, you can't protect the output file with a password, and you can't lower the quality of the input image to diminish the size of the resulting file. Also, it lacks completely a file preview function. And above all, the conversion can't be enabled, since the app is not really free. It requests a monthly, yearly, or lifetime subscription to make the conversion.
In short, XPDF: Photo to PDF Converter is an app presented as free when in fact asks to be purchased. The lack of a file preview and of ordinary conversion features makes paying for it not worth it.