How can I enforce safe image search on Google app?

A

AC Question

I bought a Moto G 2015 running Lollipop for my 15 year old son. When he either clicks on the Google app (the blue tile with the "G" in the middle), or clicks the Google search bar on the front page, he can do an open image search, which can include explicit images.

I can go to the Google app settings and click Safe Search, but he can just as easily go in and turn that off.

Here's my question: As a parent, is there a way I can enforce safe search on the Google app? If not, is there a way I can block the Google app altogether (e.g., using an app locker app?)

I've tried posting this on the Google Search forum, but haven't received any answers that work.

Many thanks.