The kids' money was the part that kept failing. Not because the math was hard, but because a five-year-old can't read a chore list and a nine-year-old doesn't believe a number she can't see. Pocket money that only exists in a parent's head teaches nothing.
So we built the kid side first: three jars instead of one balance, and a payday where the kid takes part. Then it became obvious that the household budget had to be in the same app — otherwise payday is a number you type twice and reconcile never.
CubbyJar is that: a children's money app with a real budgeting app attached, sharing one household and one set of numbers. Kids see their jars. Grown-ups see everything. Nobody sees an ad.