Most of those apps you see advertised that claim to clean your Mac to improve performance don’t do much more than a few choice free utilities.
One exception seems to be the RAM optimizer apps– a bunch are free, most are a dollar or more. What they claim to do is free up unused RAM for the app you’re using at the time.
My MacBook Air is aging and limited on RAM. Worse, I usually keep a dozen apps and utilities open at one time. It doesn’t take long for that measly amount of RAM to get clogged up. Memory Booster is one of those utilities that frees up the RAM with a neat, graphic interface.
Just like your Mac’s built-in Activity Monitor app, Memory Booster displays current RAM usage in a graph.
Click the Clean My Memory button and Memory Booster purges apps from RAM– those apps which hold onto RAM even while you’re not using the app.
In most cases, Memory Booster frees enough RAM that you can notice a mild performance boost on the app you’re using at the time.
Something similar takes place on the iPhone and iPad when you double-click the Home button to display the line of icons for recently used apps. I’d read somewhere that deleting those apps from memory does nothing. Wrong. It frees up RAM for apps you want to use now. It’s a nice trick but it’s also something Apple should build into OS X and iOS to make it easier to reclaim limited RAM.