CPU Speed Accelerator is a program designed to help you increase the amount of CPU resources assigned to your foreground apps.
Basically, this application reallocates CPU resources. This is a task which experienced system administrators can also complete by writing some commands in Mac's Terminal app (you can find them with a Google search). This program offers a simpler way to perform this task than by writing commands in the Terminal, and for this reason it comes in handy especially to inexperienced users.
Its icon is displayed on your Menu Bar. From there you can configure the program's settings according to your needs. Before activating the CPU acceleration, you need to enter your administrator password; afterwards, you can select the desired acceleration percentage and click Start.
Two things I don't like about working with CPU Speed Accelerator: it occasionally crashes and it's a bit too pricey considering that it doesn't let you terminate processes or offers you statistics (other programs from the same category offer you these two features).
My honest belief is that you can find more capable and cheaper solutions for making your apps run at their full potential. A good example for proper CPU resources allocation comes from App Tamer.
Set reminders, count time, and view clocks for various timezones.
Test the thermal limits or battery life of your Mac.
Program which graphically shows the memory.
Application that graphs your current CPU usage
This application shows the current CPU usage in a floating square meter.