If you are looking for software to analyze GPS data logs (which a J-NAV unit might export), these are the most reliable modern alternatives:
For quick serial debugging without a dedicated GPS tool, you can also use or Tera Term to open the COM port and view raw NMEA sentences directly. jnav gps analyzer download link
Often, specialized analysis tools like JNav are maintained by community developers. Searching on Garmin Forums or geocaching communities (like Groundspeak) is a great place to start. If you are looking for software to analyze
Match the to your hardware specifications (common defaults include 4800, 9600, or 115200). download the appropriate version
To successfully use the JNav GPS Analyzer, you'll need to connect your GPS module, download the appropriate version, and configure the software.