The Servoy/Web Package Manager works with Smart, Web, or ngClient solutions. It just requires Servoy 8+. However, just keep in mind that some of the things you can download from the manager might be limited to ngClient only, since thats the main focus of new stuff. In the manager, items are grouped by Components, Services, Layouts, Modules, and Solutions. The Components, Services, Layouts, and Solutions are all ngClient only (currently). However there are some items in the Modules that are useful, like svyUtils, svySecurity, etc. for smart/web clients. You can also directly access any of those from Servoy's github without going through the package manager:
https://github.com/Servoy