Educational app recommendations?

[HMum19]

I got an iPad for my 6 newly 7 yo with the intention to get some good educational apps, but am yet to find some. I downloaded a bunch only to realise you have to pay for subscriptions etc.
can anyone recommend any good free apps or websites for learning?
thank you

have you found any yet @HMum19?

But if you can afford an iPad surely you can afford a few apps?

It's the good and free that is the issue for me. Why shouldn't people who design these apps make some money?

We like Khan Academy Kids but it might be for a slightly younger age group.