how to mark tiles you stepped on

[TJR]

Is there software that can automatically mark those tiles I have
stepped on?

A quick review of my 12-conduct deaths show 4 out of 17 runs ended
when I stepped on a trap (plus some where my only pet did). I would
like to lessen my exposure.

A quick-and-dirty algorithm would be perfectly adequate: Color all
squares blue where the only white @ ever was. Ignore situations with
more than one @, or without the status line.

Helpful people on #interhack told me Interhack cannot track visited
tiles, and TAEB can but cannot be played through.