Hi,
Please share the screenshots of the iOS app so I get an idea about the app.
We don't need xamarin. I can explain what is that.
I have 4+ years of experience. I am efficient with UI/UX, web services integration, google APIs integration, third party SDKs, git etc.
I have 2 start up apps of my own. I can give my inputs to improve outcome because this is what I love to do.
Let us discuss more about your project via chat box.