Postman - The Collaboration Platform for API Development
Undesign - Free design tools and resources for your projects
DreamFactory - DreamFactory is an API management platform used to generate, secure, document, and extend APIs.
Super designer - Super designer is a collections of simple design tools to create unique designs in a a few clicks.
AWS CloudTrail - AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you.
Lean Service Creation - Open source design process and toolkit