Smallpdf - PDF document management and conversion suite
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
iLovePDF - Free online PDF tool set
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.