SparkScore - The true influence of any Twitter account
Hunter TechLookup - Create lists of websites by technology for free
xZeitgeist - The most popular tweets categorized and ranked, every day
Techmap.io - Techmap is a workplace search engine to find companies using technologies (e.g., Rails, PHP, Java, etc.) that are used internally. Finally, a "Google for Workplaces" that helps people find a place to work with technologies they love!
listshare - Create beautiful, interactive lists to share with the world.
Top Lists - A leaderboard for Twitter lists