Small task for a Xamarin.Android + Xamarin.IOS specialist

Please develop a very simple proof of concept App, that works both in Android and in IOS. There are only 2 requirements: 1 - The purpose is to keep the App running in background. In the background, the App must do some operation, like showing some iteration on the screen, or do some calculation. When you put the App in the background, for example when switching to another App, and then come back to it, the background operation must not only resume, but it must keep working in the background, so I need to see that it did not sleep. The real purpose of this is to call a WebApi (in the real App). The App also should start-up at phone start-up. And even when the App is not open, it should do the background task. Maybe the Nuget package [login to view URL] is an option. 2 - Use a slider control to let the user choose from some options. I would like to use the Android slider which is availiable in the phone configuration, when you configure the date and the time. Or something similar, which lets the user choose from a control which assimilates a wheel that he spins. Delivery must be done within 2 days. DELIVERABLES: Visual Studio 2017/2019 solution with [login to view URL], [login to view URL], and DotNet Standard 2.x class library projects. Please place your bids