I have been using this tool both for commercial and private projects. I have also got very positive feedback from one of my customers (with lots of experience from previous projects with other developers) who really appreciate how they are involved in the development and are able to follow dev progress and give comments.
The only thing that I've been missing is task dependency. But for a free tool, it's just excellent!
Ohanah is unfortunately not meeting all my needs at the moment, but the developer is releasing frequent updates with new features implemented.
In the support section you are allowed to suggest new features and vote for those you wan't implemented. This is nice, but I feel that maybe the product has been released a little bit early.
All in all, I am satisfied with the product and very satisfied with the support and response time of the developer.
I recommend this extension for it's clean and nice user interface and the support of the developer. But be sure to check the feature list before buying so you won't be disappointed.