Sprint recently jumped into the children's market with a phone it's marketing as one parents can use "to give their child the safety and communication tools they need when they are away from home." The phone is for 5-12 year olds and gives parents the ability to program up to 20 incoming and outgoing numbers. Kids can call those numbers and/or send and receive texts from them. More information about the WeGo at the link.
Judging from how early and easily our grandsons have picked up on how to use various devices, I might agree this could be a good idea and even earlier than 5. Kids seem to be born these days with an innate ability to understand the phones and ipads. And they are just as transfixed by them as adults. Look at two photos taken by each of our daughters over the weekend with both one year olds.
Jake has his thumbs in the correct position and you can see he looked up merely because he was asked to have his picture taken.
And here, Nick didn't even look up so interested is he in the device.
It's quite amazing really.