Where are you seeing this?
on the home screen at the top there is a tiny android icon next to signal strength and it has a red x on it.
I believe that is the taskiller (or a similar app) icon. it signifies that the app is currently running or trying to alert you. It could be telling you the app is set to auto-kill certain apps after periods of inactivity (very useful in my opinion) or simply a way to quick-access it from the notification pulldown.
Separate names with a comma.