What does it do?
Like Proxy Checker (or any other proxy testing program) you load in a .txt list of proxy servers in the format of host:port, and it scans through them, determines which of them respond and saves the ones that do.
How do I use it?
It's a .jar file compiled using JDK 1.7, so you'll need JRE 7 to run it. You can download that here.
Once you run it, you simply select the .txt file that contains your list of proxies (usually generated by a program like ProxyFinder), select the number of threads you want it to use (the more threads, the faster it'll work - select as many threads as you think your PC can handle for the best results) and wait for it to do its magic! When it's done checking through the list you loaded it'll automatically save the responding proxies to a .txt file called workingProxies.txt in the same directory as the program.