(Very) Quick & dirty Winforms editor to make it easy to create GeoJSON files to test GeoJsonRenderer.
Draw on the screen, save to a new file.
Does not support opening existing files, extended properties, basic properties, or anything outside of creating basic Point, LineString or Polygon geometries and saving them to a file. Frankly, it barely does that - but it does generate GeoJSON files to test the functionality of the GeoJSON Renderer.