Actually Read It Later - Save articles for reading later
The Unsplash API - No-limits, do-what-you-want API for access to 200K+ HD pics.
Firefox Advance - Experimental recommendation engine built into Firefox
PublicAPIs - Explore the largest API directory in the galaxy
ShareIt by SocialPilot - Free Content Curation and Influencer Discovery Tool
API List - A collective list of APIs. Build something.