WP Rocket - WP Rocket offers a caching plugin for Wordpress.
Shrink O'Matic - Shrink O'Matic is an AIR application to easily (batch) resize (shrink) images.
Yoast - Yoast offers plugins to improve SEO and optimize web sites and blogs.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
Wordfence - Comprehensive security plugin for WordPress.
ImageOptim - Faster web pages and apps.