TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
Metadata++ - Homepage of Metadata++, free, intuitive and powerful EXIF, IPTC, XMP, ICC, GPS viewer/editor.
ImageOptim - Faster web pages and apps.
ExifToolGUI - Graphical user interface to https://alternativeto.
TinyJPG - Compress JPEG images with perfect quality and file size
PhotoME - PhotoME is a powerful tool to show and edit the meta data of image files.