The Package Manager
Since firmware 722, the disk station manager comes with a "package manager". By using this interface, administrators are able to install add-ons, like 3rd party packages without the need of doing this on the command line or via a firmware update. Only synology package files can be used and do have the ".spk" extension.
To install a package, login as admin in the disk station manager and go to "package management". In the right window, you will get a list of installed packages and their status. Click on 'install' to start the install wizard. Upload the ".spk" file and if the file is in the right format, it will show the name of the package, version, Maintainer and a short description of what it is supposed to do. After clicking "next", it will ask on which volume it has to install. Make sure you have enough space left on that volume and after clicking next twice, the package will be installed.
Depending on the nature of the package, a package can be run and stopped. If a package contains a program that runs as a service non-stop, the package can be started via the "run" command. The status of the package will be changed from "stop" to "run". If the service is accessible via an admin page on a different portnumber, the url of that will be shown in the "management page" column (only when the package has status "run"). Stopping the service can be done via the "stop" command.
Other packages might be a "run-once program" only to install 3rd party software, which can be accessible via the 3rd party folder on the left side. Such programs are not running constantly, and sometimes can be removed after installing.
All packages do have the option to expose a logfile via the packagemanager. Click on "info" and select the tab "log". Depending on the package, it will show you the contents of the most relevant logfile of the program.