boinc-app-seti software package provides SETI@home application for the BOINC client, 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 boinc-app-seti
boinc-app-seti is installed in your system.
Make ensure the boinc-app-seti package were installed using the commands given below,
$ sudo dpkg-query -l | grep boinc-app-seti *
You will get with boinc-app-seti package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Science |
| Package | boinc-app-seti |
| Version | 8.00~svn3363-3 |
| Description | SETI@home application for the BOINC client |
| Sub Section | Science |