Both the iOS and Android version of the game are rated for all ages, so both versions should be suitable for children. Any other versions of the game aren't taken into consideration, so any other unofficial version may have more adult content and not be suitable for children.
The iOS version has over 50,000 reviews, while the Android version has over 175,000 reviews, as of March 2015. The iOS version has an average review of 3.5 stars, while the Android version has average reviews of 4.1 stars. Both apps are made by the same developer, redBit Games, free to download, and contain in-app purchases.