multitail — Extension of tail. More information: <https://manned.org/multitail>.

Tail all files matching a pattern in a single stream

multitail -Q 1 '{{pattern}}'

Tail all files in a directory in a single stream

multitail -Q 1 '{{path/to/directory}}/*'

Automatically add new files to a window

multitail -Q {{pattern}}

Show 5 logfiles while merging 2 and put them in 2 columns with only one in the left column

multitail -s 2 -sn 1,3 {{path/to/mergefile}} -I {{path/to/file1}} {{path/to/file2}} {{path/to/file3}} {{path/to/file4}}