SVGO - Tool for optimizing SVG files
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
SVG Cleaner - Generally, SVG files produced by vector editors contain a lot of unused elements and attributes...
ImageOptim - Faster web pages and apps.
Vector Artist - Vector art software designed for tablets.
E-mage - From developers to developers: a cross-platform tool for losslessly image compression.