GridPage.xaml

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="Flexibility.Shared.GridPage"
             xmlns:ios="clr-namespace:Xamarin.Forms.PlatformConfiguration.iOSSpecific;assembly=Xamarin.Forms.Core" 
             ios:Page.LargeTitleDisplay="Never">
    <ContentPage.Resources>
        <Style x:Key="gridCell" TargetType="Label">
            <Setter Property="HeightRequest" Value="80"/>
            <Setter Property="FlexLayout.Grow" Value="0"/>
            <Setter Property="VerticalTextAlignment" Value="Center"/>
            <Setter Property="HorizontalTextAlignment" Value="Center"/>
            <Setter Property="FontSize" Value="Small"/>
            <Setter Property="TextColor" Value="#556"/>
            <Setter Property="BackgroundColor" Value="#eed"/>
        </Style> 
        <Style x:Key="full" TargetType="Label"
               BasedOn="{StaticResource gridCell}">
            <Setter Property="FlexLayout.Basis" Value="100%"/>
        </Style>
        <Style x:Key="half" TargetType="Label"
               BasedOn="{StaticResource gridCell}">
            <Setter Property="FlexLayout.Basis" Value="50%"/>
            <Setter Property="BackgroundColor" Value="CornflowerBlue"/>
        </Style>
        <Style x:Key="third" TargetType="Label"
               BasedOn="{StaticResource gridCell}">
            <Setter Property="FlexLayout.Basis" Value="33.33%"/>
            <Setter Property="BackgroundColor" Value="Pink"/>
        </Style>
        <Style x:Key="fourth" TargetType="Label"
               BasedOn="{StaticResource gridCell}">
            <Setter Property="FlexLayout.Basis" Value="25%"/>
            <Setter Property="BackgroundColor" Value="LightBlue"/>
        </Style>
        <Style x:Key="auto" TargetType="Label"
               BasedOn="{StaticResource gridCell}">
            <Setter Property="FlexLayout.Grow" Value="1"/>
            <Setter Property="BackgroundColor" Value="Coral"/>
        </Style>
    </ContentPage.Resources>
     <ScrollView>
        <StackLayout>
            <Label Text="Basic Grids" 
                   TextColor="#778" 
                   FontAttributes="Bold" 
                   FontSize="20" 
                   Margin="6,6,0,6" />
            <FlexLayout Wrap="Wrap" 
                        Direction="Row">
              <Label Style="{StaticResource full}" Text="Full"/>
              <Label Style="{StaticResource half}" Text="1/2" />
              <Label Style="{StaticResource half}" Text="1/2" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource half}" Text="1/2" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource third}" Text="1/3" />
              <Label Style="{StaticResource third}" Text="1/3" />
              <Label Style="{StaticResource third}" Text="1/3" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource fourth}" Text="1/4" />
              <Label Style="{StaticResource third}" Text="1/3" />
              <Label Style="{StaticResource auto}" Text="left-over" />
            </FlexLayout>
        </StackLayout>
    </ScrollView>
</ContentPage>