Originally Posted by Stuntman
Apps don't necessarily hog memory. If there is available memory unused, Android will load apps it thinks you may use in the future into memory to use that memory. That way, when you do launch those apps, they will come up faster. Apps that are loaded into memory that are unused would not be using any CPU.
I would hope that the Android developers are more intelligent than loading apps that MAY be used into memory. I'd love to know the algorithm that could predict which apps may be used : lets load up Starbucks since he's near a Starbucks, no he paid for the Subway app - load that one instead it's just around the corner.