To remove a Windows8 store (tiled) app from the Start screen
Do a Right-click on that tile so that a checkmark shows in the upper-left corner, and then look at the context options shown at bottom of your screen.
As apropos, choose Unpin from start
Notice also the other options available as shown in this screen capture. In this sample, I am making a change for the Weather app (shown in 2nd column).
The "Turn live tile OFF" turns off the real-time updates.