Restricting Android to one demo website/webpage?

[OM2]

I want to have an Android phone on display and restrict to just one one demo website or webpage.

Is this possible?
Is there an app for it?

I'm guessing there must be as shops typically have locked phones in a similar fashion.

NOTE: I don't want a 'demo' mode as such - the website or web page will be used and interacted with.

Thanks.