Porn &Terror DNS Blocker for Mobile Phones

Porn &Terror DNS Blocker for Mobile Phones:

We are a small tech solutions provider. This time we only have a small project for a small budget. We require a parental control app that can provide a parent/ guardian full control of a gadget they acquire for a child. Most importantly a DNS blocker with special emphasis on porn material as well as terror sites.
It must be an app you install and only delete through a Parent phone if ever to be deleted.
The installation/ download should have a payment gateway for profit purposes.
What do you have for us?