prueba.xml

<StackPanel Padding="10"
            Spacing="10">

    <TextBlock Text="Windows" />
    <StackPanel Orientation="Horizontal" Spacing="10" Padding="10">
        <Button Content="Button" />
        <Button Content="Button" IsEnabled="False" />
    </StackPanel>

    <TextBlock Text="iOS" />
    <StackPanel Orientation="Horizontal" Spacing="10" Padding="10">
        <Button Content="Button"
                Style="{StaticResource iOSButtonStyle}" />
        <Button Content="Button"
                Style="{StaticResource iOSButtonStyle}"
                IsEnabled="False" />
    </StackPanel>

    <TextBlock Text="Android" />
    <StackPanel Orientation="Horizontal" Spacing="10" Padding="10">
        <Button Content="BUTTON"
                Style="{StaticResource AndroidButtonStyle}" />
        <Button Content="BUTTON"
                Style="{StaticResource AndroidButtonStyle}"
                IsEnabled="False" />
    </StackPanel>
</StackPanel>