Meta Tags - Meta Tags is a tool to debug and generate meta tag code for any website.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Devhints - TL;DR for developer documentation
Event Hunt - Startups and Tech Events Curated By Locals
Meta Tag Generator - Generate HTML code optimal for SEO, social media, & mobile.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets