Postman - The Collaboration Platform for API Development
Xmind - Xmind is a brainstorming and mind mapping application.
Ping-API - Automated API testing and monitoring.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
HTTPie for Terminal - Developers all around the world rely on HTTPie for API testing.
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.