I have a 3 (almost 4) year old daughter. I am an elementary school teacher. I have seen lots (LOTS!) of websites marketed to kids that suck them in, and there are some great Christian ones. What I have NOT seen is software or a website that is designed for kids, not just to let them play, but to let them interact with the biblical text. I would love to have (and maybe even pay a little money for) a program or website that has several child-friendly versions of the Bible, a way to search them, and some reference books and maps, time lines, etc. I'm thinking, just take the basic functions within Logos (like a Passage Guide, Biblical Facts, etc.) and make them kid-friendly and simple to use. Logos doesn't need to make Bible study fun, because allowing children to get into it themselves is engaging enough. But that's what I have not yet seen. If they could set it up for kids to interact in with the text a fun way, while keeping it simple, that would be something new. Imagine the possibilities! Something like FaithLife for kids, or a way to attach notes to a word or verse. Think of all the people that already pay you money to use your product. How many of them would pay as much (OR MORE) for their kids to use your product. (It might even be fun for the adults, shhh).
As another forum user mentioned, you could name your kid-friendly packages crayon color names instead of precious metals. "Tickle Me Pink," "Lemony Lime," and "Orange" are all options.