Bespoken Tools - Bespoken makes it easy to develop for Alexa, Google Home and Chatbots.
Alexa Skill Kit - Effortless Alexa Skill development with AWS Lambda
BotTalk - Create Alexa skills and Google Assistant actions with Markup
Effct - SAAS platform to help you publish audio content on Alexa
Voice Principles - Guiding principles for voice design, all in one place
How To Build Alexa Skills - Step by step of how to build a Alexa Skill for brands