This tab lists all the running apps on the cluster. Since filtering by status or selecting a date range is irrelevant these options aren't available; except for this difference the tab is identical to the All applications tab.

Unravel polls the Resource Manager every 90 seconds to get the resources (vCores, Memory MB, and running containers) for all running and pending apps.

Apps that run less than 90 seconds are typically not captured, i.e., unless the application is running at the exact moment the Resource Manager is polled the application data isn't captured. Therefore, for any given point the total number of apps running won't match the number of apps in All Applications if you filter on the same time.