Iphone hosts files
> Short of jailbreaking the Iphone, are there any 3rd party apps that will allow me to access the Hosts file of the Iphone?
> If you explain your aim we may be able to suggest alternatives, such as setting up your own wifi router with custom DNS entries to redirect to local network addresses.
You could also use a custom DNS server on the internet too if you need to redirect for whatever reason but you are giving us so little info that it makes it impossible to know what may help & what will fail.
https://discussions.apple.com/thread/7657173