I thought about adding a transparent layer so that my daughter and parents can draw on a story. I never thought about it from a therapy point of view, but that is just not an area I am familiar with - interesting though. I would be super happy if this can be used for that.
As far as open sourcing it goes - I have not made it open source ATM, but it is definitely something I am considering.
Is there any way you could apply here: https://apply.ycombinator.com/session/new?continue=https%3A%... and rush your build in April/May? You have ten days left to apply but it looks fine in the current state. You really have something here. I have no affiliation with YC/HN.
As far as open sourcing it goes - I have not made it open source ATM, but it is definitely something I am considering.