CloudFlare - Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.
Google Capture the Flag 2017 - Google's 2nd annual worldwide security competition
Secure My Website - A pain-free service to add SSL to your site, for non-geeks
Startup Security Program by Templarbit - Security practices & tools required to close large deals
Qloaked - Painless customer SSL for SaaS businesses
The Security Checklist - The Practical Security Checklist for Web Developers