iPhone
The problem with both of these filters is that they are designed to protect children, not adults. As such, whoever downloads the
browser also knows the password and can bypass the filters. In addition, these filters are not foolproof. In short, at this point in time there is no satisfactory filtering solution to protect iPhones from accessing unsuitable websites.
To further protect your iPhone, you should download an app lock and lock the app store,Safari browser and YouTube to guarantee that unsuitable content will not be accessible.
There is one additional solution for the iPhone: mymobilewatchdog.com provides a good monitoring service, but this service has issues and may be difficult to use.