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

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

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

Coggle - Coggle is a simple, beautiful, powerful way of structuring information.

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