gwaterfall binary package in Ubuntu Focal amd64

 This program facilitates comparison of various fonts and font
 rendering parameters.
 .
 It displays sample lines of text in sizes from 5 to 36px
 simultaneously and allows changing of font size range and increment,
 hinting, autohinting, anti-aliasing, subpixel smoothing, and aspect,
 immediately showing the changes on the screen. All Unicode
 characters are divided into blocks of 128 characters, and user can
 choose block of 128 characters to use as sample line of text.

Source package