The Problem:
Kids who grow up in interfaith homes do not really have a proper way to be educated about religion. One specific religious school doesn’t work.
The Business
An online religious school/learning program for children whose parents want religious/spiritual exposure, but don’t want to go with one formal religious school experience. Sunday school for interfaith kids.
Doableness
You could do it online, but there needs to be some in-person component as well. Part of the good things about religious school is a bond with other kids. You would need to find a way to replicate that if the program was online.
My Thoughts
More and more people fit into this category, but less and less people seem to be interested in any kind of religious schooling for kids. And those that do still put their kids into religious schooling are likely to be ever more focused on only their own religion. All that said, I think we would be surprised at how many people come out of the woodwork with their kids to participate in something like this.
The online interfaith Sunday School would be completely branded as non religious. A spiritual school where children learn about different religions and learn about spirituality.