When our first daughter Devina was born, we decided we weren't going to have her interact with electronics until she could create with them . We want our children to be creators, not just consumers, of technology. She's now three years old, and we've been looking for the right way to introduce her to technology. After a lot of looking, we've found something amazing -- a system called Osmo. (About $95 on Amazon plus $30 or so for each add-on kit).
Osmo works with an iPad -- we're using an old iPad and it's been fully compatible -- with a system of software + physical pieces, as well as a red mirror that covers the iPad's camera, focusing the camera on the table just in front of the iPad.
The genius of Osmo is its range. There's Osmo software for putting colored shapes together, for drawing , for math, for coding , for cooking , and more. It's an expandable system that's designed for ages 4 through 12 (although our three year old has been totally into it), meaning it can grow with a child for quite a while, which isn't something that can be said for most learning systems. That's the magic of software.