CloudFlare - Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.
Cloudflare Spectrum - DDoS protection for TCP services
Google Project Shield - Google's DDoS protection service
SSL Alerts - Free service to send SSL certificate expiration alerts
Vanta - Automate compliance, simplify security.
Qloaked - Painless customer SSL for SaaS businesses