What are some alternatives?
When comparing Iris and Nifty Project Management, you can also consider the following products
Moka - Moka is a Gnome Shell theme that uses simple geometry & basic colouring.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Eyeleo - EyeLeo is a handy PC application that reminds you to take a break for your eyes.
Atina - Simple project management tool
Materia - Materia is a development environment to build advanced mobile and web applications.
Flow - Stop managing projects from your inbox.