Micromappa - very easy GTK+ python application to view geojson files. Used osmgpsmap module (http://nzjrs.github.com/osm-gps-map/).
- Open geojson files
- Used OpenStreetMap tiles
- Change data style (color,size and transparency)
- Save map to .png
https://github.com/gisplit/micromappa/blob/master/screenshot.png