This is a small script that follows UNIX laws. Do one thing and do it well. A simple text plain file is created in your $HOME/.todo.txt And is manipulated with some tools like grep/sed, tl written in Shell Posix.
I was tired of using more "complex" software like todo.txt. I wanted something very simple, that followed the KISS and UNIX philosophy. Written in 50 lines, removing comments and blank lines.
Add tl script to /usr/bin/tl and give execute permission, chmod +x tl. You can add a new task with add, list with @ and end the task with end