Edit points, lines and polygons
  1. On the Startup menu, touch Edit Map <your_map_name>
  2. Move the cursor to where you want start a line feature*
  3. On the upper Edit toolbar, touch Start Line
  4. Move the cursor to the next coordinate point on the map and lift your finger off the screen
  5. Repeat step 4. for all the coordinate points along the line
  6. To end the line, touch End
* Line is the default feature type. To place a point or polygon, first touch Type/Symbol and select the desired symbol

See Video:

YouTube Video