No, RivalFlow works without needing any other tools. To make page updates, you need to be able to edit the pages (blog platform, management system, etc.)
However, there is an opportunity to connect GSC to RivalFlow for any websites you have access to. That lets you track your performance before and after RivalFlow improvements, right in the app.
Tip: You can get RivalFlow page suggestions for any website. Many agencies use it to pitch content improvements to potential clients.