I have a passing familiarity with Scratch [1], which I'm now looking into more, but am hoping others can share their knowledge and experience in this area.
[1] https://scratch.mit.edu/
Scratch works reasonably well on a tablet though it limits the kinds of inputs you can use a bit - keyboard/mouse events require a bit of extra hoop jumping.
Physical programming toys may be better for some kids since they are more tangible. Things like Botley and other programmable robots, and physical logic engines like Turing tumble have great illustrative value.
Your child can learn programming when they are fourteen or fifty-four.
They can only spend their childhood with you right now.
And you with them.
They are interested in what you do because they are interested in you. Put them on your lap and pair program...
OK so there's a tool, pair programming.
Good luck.