Greetings,
I have already developed VPN app which is very similar to UFO VPN that you have shared in description.
I can show the demo of the app that I have built.
It is having 95+ proxy servers. App is currently free an open source.
You can also put ads in the app.
I am a Mobile app developer with experience in android and iOS both. I have 4 + years of experience with mobile app development. I can work in both the platform.
Lets discuss more on chat
Regards,
I am a mobile developer with 8 years of experience. My skills include iOS, Android, React-native, JavaScript, node.js, React, Vue, WeChat Mini Program an so on