In the Jupyter ecosystem, data visualization is usually done with “widgets” created as notebook cell outputs. While this mechanism works well in some circumstances, it is not well-suited to presenting “ds9-like” interfaces that are long-lived, interactive, and visually rich. Unlike the traditional Jupyter notebook system, the newer JupyterLab application provides a sophisticated extension infrastructure that raises new design possibilities. Here we present a novel user experience (UX) for interactive data visualization in JupyterLab that is based on an “app” that runs alongside the user's notebooks, rather than widgets that are bound inside them. We have implemented this UX for the AAS WorldWide Telescope (WWT) visualization tool and will demonstrate it in operation. JupyterLab's messaging APIs allow the app to smoothly exchange data with multiple computational kernels, allowing users to accomplish tasks that are not possible using the widget framework. While we have developed this UX for WWT, the overall design is portable to other applications and has the potential to unlock a variety of new user activities that aren't currently possible in “science platform” interfaces.