Hello Ricky,
If I understand correctly you are asking if you need to download an app to use Parental Controls on a childs device. Parental Controls, or Restrictions as they are called on the phone do not require any separate download, and is built right into the iOS. Just use the article at the top of your post and you should be good to go:
About Restrictions (parental controls) on iPhone, iPad, and iPod touch
If that is not what you are saying, then can you clarify for me?
Thank you for using Apple Support Communities.
Take care,
Sterling