Xmind - Xmind is a brainstorming and mind mapping application.

Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.

Newton Mail - Newton is a fully featured mail client available for Android, iOS, macOS and Windows.

MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.

myMail - myMail is the smart email app for managing all your accounts on iOS and Android.