Although developers have been creating VBA add-ins for Excel since 1993, Excel 2013 and Excel 2015 offer an Excel App Store featuring JavaScript apps. Right now, the apps are limited to read-only access to a range of cells and will then create some new visualization in an application window.
In Excel 2013, go to Insert, Apps for Office. Many apps are free.
- This is the free Bubbles App. On the screen, the bubbles animate and move.