Scratch-Plot by KBH is a fast-reach, ease-of-use plotting program with a simple file structure. And so Scratch-Plot is suitable for minor design projects...on the fly, off the cuff or on site. Of course use of Scratch-Plot is like making an electronic design-on-a-napkin...
The program plots by North and East coordinates but can also plot by azimuth and distance. The azimuth and distance plot can hold a starting location with its "Fan" feature or move up to each new location.
Scratch-Plot can plot points, numbers, lines, or tangent curves...
The Scratch Plot files can be opened with a text editor and understood. So any application developer can output files for Scratch-Plot. And Scratch-Plot files can be edited with a text editor or user coordinates can be found in the file with the text editor.
Here is a user link to Scratch-Plot: