The lesson that saving pays off, made literal.
Set an annual interest rate — anywhere from 0% to 12.5% — on a child's savings pot, and Kupa3 automatically credits interest to their balance on the first of every month. No spreadsheets, no manual math: just a real, if small, taste of compounding that rewards patience.
In a child's settings, drag the Savings Interest Rate slider up to 12.5% per year. Kupa3 immediately shows what that rate earns per month on the current balance.
On the 1st of the month, a "Monthly interest" line appears in the savings history with the exact rate and amount credited — proof, not just a promise.
Choose a rate that fits your family's philosophy — even a modest rate is enough to teach the concept.
A scheduled Cloud Function calculates and credits the interest automatically on the 1st of each month, logged like any other transaction.
Show your child the interest transaction when it lands — it's the moment 'saving pays off' stops being a saying and becomes something they've seen happen.
Higher rates make the lesson land faster for younger kids who need to see the effect sooner to stay motivated.
Pair interest with a savings goal — watching a target get a little closer 'for free' each month is genuinely exciting for kids.
Revisit the rate occasionally as a family conversation — it's a natural way to introduce what interest rates mean in the real world.