Identify the web site loaded in web view iOS application?
To determine the web site, you will need to intercept the network traffic travelling between your iPhone and your Internet Service Provider (ISP).

To do this you need to set your phone to use WiFi and to pass network traffic through a proxy. Proxies include squid and Charles.

A good proxy will offer log files and allow you to see server addresses and, if not encrypted, requested URLs.

Alternatively, you could contact the application developer and ask.