Wow, so much misinformation here, as a dev this thread is pretty funny
Yes, the app probably does what it says. Somebody else already got it right - i'll just demand all of the memory for itself, and the OS will quietly kill any apps that are sleeping in the background. It then releases all of that memory, and congratulations: your memory is mostly empty!
But why the hell do you want your memory emptying?
It won't make the system any quicker, because whenever an app needs more memory it asks for it and the system frees it up. If you do this in advance then yes, you won't have to wait for the system to do this, but you'll have wasted much more time running the memory freeing app so overall YOU LOSE.
Worse, when you come to open an app that was in the background, you've killed it. That means it has to load up from scratch and you have to get back to where you were. Again - YOU LOSE.
Battery life? Those background apps aren't actually running, they're only waiting in memory. The battery hit from this is near zero. But if you've killed them, when you open them again they have to do quite a bit of work to start up which eats battery. And clearing the memory also eats battery. Again, YOU LOSE.
So, an app that's bad for speed, bad for productivity, and bad for battery life. What a great idea
