PublicAPIs - Explore the largest API directory in the galaxy
BotList - An app store for bots
The Unsplash API - No-limits, do-what-you-want API for access to 200K+ HD pics.
ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.
API List - A collective list of APIs. Build something.
ChatBottle - Chatbots Search Engine