Memory Improve is a memory management utility. It allows you to keep track of the memory your programs are using and, if needed, take some of that memory back. That is called "claiming" memory (and often does more harm than improves anything).
The free version of Memory Improve Ultimate is quite complete as it is. It allows you to graphically see your memory usage. It also lets you change processor time and visual effects so that your memory doesn't take a hit from CPU usage. Processes can be responsible for high memory usage, and this program can kill them for you. Or you can set parameters to kill certain processes and claim the memory they are using.
Graphically, the program boasts a tabbed interface, with an overview of your system in the main window. It shows a graphical representation of your memory usage, the paging files in use, and the CPU load. There is a Defragmentation feature that seemingly improves your virtual memory to compensate for low RAM. As an added bonus, the application can be set to automatically free memory at intervals or compress it. You can also set exceptions for these operations.
In the System tab, there are various other features for optimizing your computer, including some for disabling paging executive data and using large system cache. All in all, I think that the Free version of this application is enough to optimize any system and, although the performance gain you will experience is not huge, definitely helps with slow(er) systems.