Pro nodes are only available in Vuo Pro, not in the regular Vuo or the free trial. If a node is pro, then the Node Documentation Panel says so at the bottom. If you try to open a composition containing pro nodes using non-Pro Vuo, then you’ll be warned that you won’t be able to run the composition.
If you plan to share a composition that contains pro nodes, keep in mind that Vuo users without Vuo Pro can’t run the composition. If you want others to be able to use your composition even if they don’t have Vuo Pro, consider exporting it to an app.
Currently, pro nodes aren’t available when using compositions in other applications.