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