Meta Tags - Meta Tags is a tool to debug and generate meta tag code for any website.
Booking.com - Find your next stay. Search deals on hotels, homes, and much more...
Devhints - TL;DR for developer documentation
Sygic Travel Maps - Itinerary planner for independent travelers
Meta Tag Generator - Generate HTML code optimal for SEO, social media, & mobile.
Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.