I contacted Christian Boer to get more information about Dyslexia, and this is what I found out..
first of all, Dyslexia is not free. Currently, Christian is selling this font only in The Netherlands but soon plans to sell this font in other regions. It looks like he wants to sell to bigger groups (like schools, other organizations that focus on Dyslexia) instead of individuals to keep costs low (although his youtube page suggests that he wants to sell to individual users as well).
Watch the video to know more about Dyslexia, and how it would help Dyslexic readers.
You can contact Christian Boer here.