GridView с квадратными ячейками?
если вам нужен не дашбоард, а грид с квадратными картинками, создайте свой класс, унаследуйте его от ImageView и переопределите метод onMeasure() примерно так:

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	int measuredWidth = getMeasuredWidth();
	setMeasuredDimension(measuredWidth, measuredWidth);
}

Хм, не знаю как подцепить файл сюда. Но может быть вот такой компонент подойдет?

public class DashboardLayout extends ViewGroup {
	private final static String TAG = DashboardLayout.class.getName();

	private final static int DEFAULT_COLUMNS = 3;

	private int columns;

	public DashboardLayout(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DashboardLayout);

		try {
			setColumns(a.getInt(R.styleable.DashboardLayout_dashboardColumns, DEFAULT_COLUMNS));
		} finally {
			a.recycle();
		}
	}

	public DashboardLayout(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public DashboardLayout(Context context) {
		this(context, null);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

		int totalChildWidth = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();

		int visibleCount = getVisibleCount();
		if (visibleCount > 0) {

			int childWidth = totalChildWidth / columns;
			int childHeight = childWidth;

			int childWidthSpec = MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY);
			int childHeightSpec = MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.EXACTLY);

			for (int i = 0, N = getChildCount(); i < N; i++) {
				final View child = getChildAt(i);
				if (child.getVisibility() != View.GONE) {
					child.measure(childWidthSpec, childHeightSpec);
				}
			}
		}

		setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {

		int childLeft = l + getPaddingLeft();
		int childTop = t + getPaddingTop();

		for (int i = 0, N = getChildCount(); i < N; i++) {
			final View child = getChildAt(i);
			if (child.getVisibility() != View.GONE) {
				child.layout(childLeft, childTop, childLeft + child.getMeasuredWidth(),
								childTop + child.getMeasuredHeight());

				childLeft += child.getMeasuredWidth();
				if (childLeft + getPaddingRight() >= r) {
					childLeft = l + getPaddingLeft();
					childTop += child.getMeasuredHeight();
				}
			}
		}

	}

	/***
	 * Set number of columns. By default DashboardLayout uses 3 columns
	 * 
	 * @param value
	 *            - number of columns
	 */
	public void setColumns(int value) {
		if (value != columns) {
			columns = value;
			requestLayout();
		}
	}

	/***
	 * Returns number of columns.
	 * 
	 * @return number of columns
	 */
	public int getColumns() {
		return columns;
	}

	private int getVisibleCount() {
		int count = 0;
		for (int i = 0, N = getChildCount(); i < N; i++) {
			if (getChildAt(i).getVisibility() != GONE) count++;
		}

		return count;
	}

}



Еще надо положить в res/values/attr.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="DashboardLayout">
        <attr name="dashboardColumns" format="integer" />
    </declare-styleable>

</resources>
