Island Saver is a fun little educational game created by the UK bank, NatWest, to help kids understand the concept of money saving, paying tax, exchange rates, and even how to avoid scams.
While the game is fun, bright and colourful, there are some aspects that are not as straightforward as you would expect for a game aimed at kids, so I would recommend that this is played with a parent on hand to help guide the child (and possibly to help read out the text as this is key to the money themes in the game).
I was very sceptical about this game, as it is commissioned by a bank, and is completely free with no in app purchases (there is an optional DLC that costs £3.99 but this is not required to have a great time with the game), but I was actually really surprised.
I only downloaded the game so that I could get the 1000G, but ended up enjoying myself more than I thought I would. Especially considering I was playing alone with no kids. hahaha