SAN FRANCISCO -- YouTube is a repository of clips that range from exceedingly educational to suggestively explicit. So to make sure younger fans of Google's online video library have a more age-appropriate experience, its engineers have come up with a new app called YouTube Kids.

The free app launches Feb. 23, and is available for Android and iOS devices.

"Parents were constantly asking us, can you make YouTube a better place for our kids," says Shimrit Ben-Yair, the project's group product manager, noting that family-friendly fare is a booming business on YouTube. "(Year over year) we've seen 50% growth in viewing time on YouTube, but for our family entertainment channels, it's more like 200%."