I purchased a cover for my N7. I can see that it is working to stop the screen display (and sleep?) when I close it because as I swing the cover into position within an inch of it closing the screen goes to black. And when I open it the screen takes a half second then comes back on.  That works.

But I think some apps may not be going to sleep when I shut the cover. I can shut the cover with a full battery charge and come back a day later and the battery is drained.  I haven't figured out which ones are causing the problem.  Definitely I saw this when I used an app to watch video from Twit.tv - there are a few apps out there for this and I'm not sure which one I was using.

Is there a trouble shooting technique that I could use to figure out if apps are using power when the cover is supposedly putting the N7 into sleep?