Memory Diag is a Mac application that helps you optimize the performance of your system by reducing the amount of CPU resources that are being used at any given moment. This program sits quietly on your Menu Bar where you can find information regarding memory usage, details about the memory slots of your Mac, and three main window themes.
In my testing, I compared the statistics offered by Memory Diag with the information provided by Activity Monitor app (default Mac tool that allows you to check memory usage, disk activity, etc.). Both of the aforementioned sources brought me identical details, hence I'd say this tool offers accurate info.
Afterwards, I clicked the Optimize button to see how the app can help me with the memory usage (meanwhile, I was comparing its statistics with Activity Monitor's info). To my surprise, the program really reduced the amount of CPU resources that were being used at the time.
Hence, this application does exactly what's stated on the homepage of the developer: it optimizes the performance of the system.
In my opinion, it's worth installing this freeware tool on your Mac mostly because it helps you improve the way your system operates by freeing up memory. The application is simple to handle even by regular Mac users, uses a small amount of CPU resources, and you don't have to pay for it.