comix software package provides GTK Comic Book Viewer, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install comix
comix is installed in your system.
Make ensure the comix package were installed using the commands given below,
$ sudo dpkg-query -l | grep comix *
You will get with comix package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | X Window System software |
| Package | comix |
| Version | 4.0.4-3 |
| Description | GTK Comic Book Viewer |
| Sub Section | x11 |