The Security Checklist - The Practical Security Checklist for Web Developers
Boss - Github, now with bounties
SafeBase - SafeBase is the interactive security portal to share your security posture, automate access to sensitive compliance information, and subscribe to vendor security program updates.
Bugcrowd - Harness the largest pool of curated and ranked security researchers to run the most efficient bug bounty and penetration tests
WordPress Security Scanner - Check if your WordPress site has known vulnerabilities
Bounties Network - Complete tasks, earn crypto