To create a new shape:

1. Select shape tool from toolbar.
2. Drag on cavas to create a new shape or tap an existing shape to select the shape.
3. For shapes that support modifying, some orange control points will be shown. Drag on these points to modify the shape.

To edit an existing shape:

1. Select shape tool from toolbar.
2. Tap an existing shape on canvas.
3. You may now start editing the shape using the orange control points, or tap the lasso button on the popup menu to continue editing in lasso mode.