Hello Sir,
Flawlessly we have done multiple jobs in mobile app development and we are technophile in app frontend and backend which includes:-
✍ Xamarin forms/Xamarin Android/Xamarin iOS
✍XAML C#, .NET, Visual Studio 2017
✍Xcode (I've been working with Xcode since version 3), Objective C and Swift
✍ MVVM and Binding technology
✍Packages from NuGet and Components from Xamarin Store
✍modernhttpclient to consume Rest API.
✍ Distribution of beta builds to beta testers through TestFlight
✍local notification, push notification handling by using Azure(We may use PNS directly if you want)
✍Many iOS SDK frameworks like UIKit, CoreLocation, QuickLook, Store Kit, etc.
I have in the past work for many an app development project which required extensive detailing. And, you can go through my Xamarin portfolio to know more.