Not as safe as I thought it would be.
I downloaded this, added the security stuff and it brings up things like 20th century fox stuff that I dont want me 3 years old to play. It has a block option but to block all would take forever.
It asked for content and age things like this and some of the videos with guns and things should be saved for older kids and adults, not 3 year olds. I removed this app due to its inappropriate content.
Sunnier73 about YouTube Kids, v3.07.12