A WPF grid with resizable rows, where resizing a row does not change the size of other rows.

BindableGrid.cs

// derived from https://stackoverflow.com/a/26540204
public class BindableGrid : Grid
{
    bool spacingRow = false;
    public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register("ItemsSource", typeof(IEnumerable), typeof(BindableGrid), new FrameworkPropertyMetadata(null, OnItemsSourceChanged));

    public static readonly DependencyProperty ItemTemplateProperty = DependencyProperty.Register("ItemTemplate", typeof(DataTemplate), typeof(BindableGrid), new FrameworkPropertyMetadata(null, OnItemTemplateChanged));

    public IEnumerable ItemsSource
    {
        get { return (IEnumerable)GetValue(ItemsSourceProperty); }
        set { SetValue(ItemsSourceProperty, value); }
    }

    public DataTemplate ItemTemplate
    {
        get { return (DataTemplate)GetValue(ItemTemplateProperty); }
        set { SetValue(ItemTemplateProperty, value); }
    }

    public static void OnItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BindableGrid)d).OnItemsSourceChanged((IEnumerable)e.OldValue, (IEnumerable)e.NewValue);
    }

    public void OnItemsSourceChanged(IEnumerable oldValue, IEnumerable newValue)
    {
        INotifyCollectionChanged oldValueNotify;
        if ((oldValueNotify = oldValue as INotifyCollectionChanged) != null)
        {
            oldValueNotify.CollectionChanged -= ItemsSourceCollectionChanged;
        }

        INotifyCollectionChanged newValueNotify;
        if ((newValueNotify = newValue as INotifyCollectionChanged) != null)
        {
            newValueNotify.CollectionChanged += ItemsSourceCollectionChanged;
        }
    }

    public static void OnItemTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BindableGrid)d).OnItemTemplateChanged((DataTemplate)e.OldValue, (DataTemplate)e.NewValue);
    }

    public void OnItemTemplateChanged(DataTemplate oldItemTemplate, DataTemplate newItemTemplate)
    {
    }

    private void ItemsSourceCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.Action == NotifyCollectionChangedAction.Reset)
        {
            RowDefinitions.Clear();
            Children.Clear();
        }
        else if (e.Action == NotifyCollectionChangedAction.Add)
        {
            AddItems(e.NewItems);
        }
        else
        {
            throw new InvalidOperationException(string.Format("Action '{0}' is not valid.", e.Action));
        }
    }

    private void AddItems(IList items)
    {
        if(!spacingRow)
        {
            spacingRow = true;
            RowDefinitions.Add(new RowDefinition
            {
                Height = new GridLength(1, GridUnitType.Star),
            });
        }
        foreach (var item in items)
        {
            RowDefinitions.Insert(Children.Count, new RowDefinition
            {
                Height = new GridLength(100, GridUnitType.Pixel),
                MinHeight = 40,
            });
            var contentPresenter = new ContentPresenter();
            contentPresenter.SetValue(ContentPresenter.ContentTemplateProperty, ItemTemplate);
            contentPresenter.Content = item;
            SetRow(contentPresenter, Children.Count);
            Children.Add(contentPresenter);

            RowDefinitions.Insert(Children.Count, new RowDefinition { Height = GridLength.Auto });
            var gridSplitter = new GridSplitter
            {
                Height = 2,
                Background = new SolidColorBrush(Color.FromArgb(127, 127, 127, 127)),
                VerticalAlignment = VerticalAlignment.Center,
                HorizontalAlignment = HorizontalAlignment.Stretch,
            };
            SetRow(gridSplitter, Children.Count);
            Children.Add(gridSplitter);
        }
    }
}

Usage:

<localViews:BindableGrid ItemsSource="{Binding ItemsList}">
    <localViews:BindableGrid.ItemTemplate>
        <DataTemplate>
            <Control/>
        </DataTemplate>
    </localViews:BindableGrid.ItemTemplate>
</localViews:BindableGrid>