freecontact software package provides fast protein contact predictor, 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 freecontact
freecontact is installed in your system.
Make ensure the freecontact package were installed using the commands given below,
$ sudo dpkg-query -l | grep freecontact *
You will get with freecontact package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Science |
| Package | freecontact |
| Version | 1.0.21-4+b2 [mips], 1.0.21-4+b |
| Description | fast protein contact predictor |
| Sub Section | Science |