What are some alternatives?
When comparing Iris and Whimsical Mind Maps, you can also consider the following products
Moka - Moka is a Gnome Shell theme that uses simple geometry & basic colouring.
Mind Map by RealtimeBoard - More than your average mind map
Materia - Materia is a development environment to build advanced mobile and web applications.
Transno - Only one tap transforms a note to mind map
Eyeleo - EyeLeo is a handy PC application that reminds you to take a break for your eyes.
Mind Mapped - Create mind maps on the blockchain