Android VPN - Xamarin - Firewall Filter

Create a simple VPN class that will filter (stop) any TCP or UDP messages except from the primary application. Using the VpnService, create a class that'll install a VPN to capture all traffic. If traffic (any) is using Wi-Fil, then traffic can pass. If traffic is using Cellular data, then only traffic from a specifically application will pass (or to a specific IP address). Basically adding the function of NoRoot Firewall to my application. NoRoot Firewall does exactly what I want but I don't want to have to install NoRoot firewall on all my clients devices. My software sends data to a server and while Cellular data is in use, I don't want other software to use up bandwidth. When attached via Wi-Fi, then all traffic can pass. I was going to write this myself, but just don't have the time. This is a good place to start: [login to view URL] This NEEDS to be written in C# using Xamarin. Should just be a class based on VpnService that can be started as a service (or similar).