In this version, you can create up to 4 cubic Bézier curve segments (13 control points, because the last point of each segment is the first point of the next).
Touch the screen to add control points, move them by dragging.
Touch the to display the convex hull of each set of 4 control points. You can now move the points around and see that a Bézier curve always stays within the convex hull of its control points.
Touch the to see a line going through the third and fourth point of each segment. The second point of the next segment should be at the other end of that line in order for the curve to be C1 continuous at the connecting point.
Finally, touch the to delete the last control point, and the for a usage summary.