Of course. ScriptVocalizer is an independent app. You received ScriptVocalizer as a complementary access with your Promoyze club. But, if you like to get more features in your ScriptVocalizer, you can buy any of it's upgrades or up-sells. You will find the upgrade sales page links inside the ScriptVocalizer App Content Area.
Or, you can simply contact support for any specific upgrade/up-sell link you might be interested in.