What are some alternatives?
When comparing Stormboard and Microsoft Whiteboard, you can also consider the following products
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
OpenBoard - The OpenBoard software is an interactive white board software.
XMind - XMind is a brainstorming and mind mapping application.
Jamboard - Interactive Business Whiteboard | G Suite
MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.
Conceptboard - Instant Whiteboards for Teams & Projects