watchcat combines good things about watch and cat.
it also might be useful on bsd systems that are lucking watch afaik.
$ watchcat --help
watchcat 1.0
Usage: watchcat [OPTIONS] -- COMMAND [ARGS...]
watchcat [OPTIONS] -f FILENAME
Options:
-n, --interval INTERVAL Update interval (e.g., 2s, 500ms)
-f, --file FILENAME Monitor file changes
--clear Clear screen between updates
--no-clear Do not clear screen between updates
(In command mode, clear is default)
(In file mode, no-clear is default)
-d, --diff Highlight differences (useful for commands)
-t, --timestamp Show timestamp when changes occur
--help Show this help
also you can watch [this video](https://toobnix.org/w/taHbL5P534jHNFyZJBPrv].