I don't know if it exists but my friend and I are thinking of making a VR app to help toddlers learn their first 100 words in a foreign language. Our idea is to use 360-degree images with annotations to teach words using Google cardboard or any other VR device.
There is a rich dataset of 360-images by MIT[1] if anyone is interested in taking up this project.
For some reason the idea of putting a VR visor to a toddler is unsettling to me. Maybe I am getting old...
The Oculus Rift and Samsung Gear VR Health & Safety documents state that they should not be used by children under the age of 13. Same for the Google Daydream and Sony states that their VR is not for use by children under the age of 12.