A VPN between app and server wouldn’t hide the ip address because the client needs to know the endpoint. (DNS or IP). You could hide the server itself by putting it behind a NAT (router, firewall, 2nd server) or something like this. But the IP address of this devices will be exposed.
Method 2: By using Proxy. Proxy servers are nothing but the simplest form of VPN service. When you make use of Proxy servers, Websites and apps will show a different IP-address. There are many online Proxy servers available which you can use to hide your Mac system’s IP-Address. A transparent proxy does pass along your IP address, so it won't do a very good job of hiding your identity. An anonymous proxy doesn't pass along your IP address, but it does identify itself as a proxy server when connecting with the other server, while a distorting proxy provides an incorrect IP address. A high anonymity proxy doesn't pass How do I hide my IP address? The most common method to hide your IP address is to use a proxy server in one form or another. A proxy server is a computer that offers a computer network service to allow clients to make indirect network connections to other network services. A distorting proxy server provides a false public IP address to the network but does not hide the fact that the client is using a proxy to access the web. Using this type of proxy will allow someone from one location to access content that may only be available in another area.
A distorting proxy server provides a false public IP address to the network but does not hide the fact that the client is using a proxy to access the web. Using this type of proxy will allow someone from one location to access content that may only be available in another area. Berkeley Electronic Press Selected Works
Private Socks5 & HTTPs proxies from Proxy-Seller for any purpose. Do you want to buy a proxy here? - Certainly you will get a fast dedicated IP address with a selection of 100 Networks / 300 Subnets, with a 1Gb/s speed channel, 24/7/365 customer support.
These proxy servers make it seem as if the proxy is the client by only including the REMOTE_ADDR header with the IP address of the proxy server. Anonymous proxies, transparent proxies, and high anonymity proxies are forward proxies as they basically forward the web requests to and from the destination servers.