Xmind - Xmind is a brainstorming and mind mapping application.
Zeplin - Collaboration app for UI designers & frontend developers
FreeMind - FreeMind is a premier free mind-mapping software written in Java.
Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Abstract - A secure, version-controlled hub for your design files