WP Rocket - WP Rocket offers a caching plugin for Wordpress.
Virusdie - All-in-One cloud-based, simple, powerful and gorgeous website security tools built for everyone.
Yoast - Yoast offers plugins to improve SEO and optimize web sites and blogs.
Sucuri - Website Protection, Malware Removal, and Blacklist Prevention
Wordfence - Comprehensive security plugin for WordPress.
Event Espresso - Event Espresso offers event registration and ticketing management plugin for WordPress.