erlang-yapp software package provides Erlang application for deploying Yaws webserver applications, 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 erlang-yapp
erlang-yapp is installed in your system.
Make ensure the erlang-yapp package were installed using the commands given below,
$ sudo dpkg-query -l | grep erlang-yapp *
You will get with erlang-yapp package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Web Servers |
| Package | erlang-yapp |
| Version | 2.0.4+dfsg-1 |
| Description | Erlang application for deploying Yaws webserver applications |
| Sub Section | httpd |