Convert SPICE Model Netlist to Schematics
I am only aware of two alternatives to the commercial software you linked in your question.  There could be others, and if anyone comments with more suggestions I can edit the answer.
1.) NetlistViewer
2.) LTspice Schematic Builder
I have little to no experience using either of the above.  I've manually &quot;decompiled&quot; netlist to LTspice schematic a couple times, but it's very tedious and only useful for learning the process or honing your skillz with SPICE syntax.  Therefore, I generally don't recommend the manual process unless the netlist is only a few lines.