Guess so. And the "store away" account is likely in a money market fund where they either take all returns or a significant chunk of it. If the product is free, you're the product.
Product will be subscription based (<$5) and you keep all the interest, which could pay off subscription depending on monthly spending. Too many fintech’s rely on percentage of volume and it’s not really reliable.
Because it automatically stores-away money for each purchase. Some users enjoy the piece of mind of not having a bill at the end of month, and this provides the funds in order for that to happen. For me, I personally hate budgeting with credit cards and hate seeing my statement at the end of the month cause my checking balance is not accurate then. I would use a debit card more, but I get little protection and no benefits. This app may not be for you and that's okay!