asmon software package provides system resource monitor dockapp for Afterstep and WindowMaker, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install asmon
asmon is installed in your system.
Make ensure the asmon package were installed using the commands given below,
$ sudo dpkg-query -l | grep asmon *
You will get with asmon package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | X Window System software |
| Package | asmon |
| Version | 0.71-5 |
| Description | system resource monitor dockapp for Afterstep and WindowMaker |
| Sub Section | x11 |