Linux App for IP Masquerading & NAT

I'm seeking a skilled developer to create a Linux application for Network Address Translation (NAT) with a primary focus on IP masquerading. This application needs to be hosted on an EC2 instance in AWS or an Virtual Machine in Azure

Key Requirements:
- The application must support IPv4
- It should facilitate both TCP and UDP protocols.
- User friendly GUI

Ideal Skills and Experience:
- Extensive knowledge of Linux and NAT.
- Proficient in IPv4 and both TCP/UDP protocols.
- Prior experience in developing network applications will be an added advantage.
- Knowledge of Linux IP tables