Essential Studio for Xamarin.Forms
Waterfall Chart and Graph

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:ChartExample"
             xmlns:chart="clr-namespace:Syncfusion.SfChart.XForms;assembly=Syncfusion.SfChart.XForms"
             x:Class="ChartExample.MainPage">
    
    <ContentPage.BindingContext>
        <local:ViewModel/>
    </ContentPage.BindingContext>
	
	<chart:SfChart>
			
		<chart:SfChart.PrimaryAxis>

			<chart:CategoryAxis />

		</chart:SfChart.PrimaryAxis>

		<chart:SfChart.SecondaryAxis>

			<chart:NumericalAxis />

		</chart:SfChart.SecondaryAxis>

		<chart:WaterfallSeries ItemsSource="{Binding Data}" XBindingPath="Category" YBindingPath="Value" SummaryBindingPath="IsSummary"/>
               
	</chart:SfChart>
	
</ContentPage>

public class Model
{
    public string Category { get; set; }

    public double Value { get; set; }

    public bool IsSummary { get; set; }

    public Model(string category, double value, bool isSummary)
    {
        Category = category;
        Value = value;
        IsSummary = isSummary;
    }
}

public class ViewModel
{
    public ObservableCollection<Model> Data { get; set; }

    public ViewModel()
    {
        Data = new ObservableCollection<Model>()
        {
            new Model("Sales", 145, false),
            new Model("Staff", -65, false),
            new Model("Balance", 58, true),
            new Model("Others", 12, false),
            new Model("Tax", -30, false),
            new Model("Profit", 45, true),
            new Model("Inventory", -12, false),
            new Model("Marketing", -25, false),
            new Model("Net Income", 25, true),
        };
    }
}