Can we still use Sleepyhead?

I saw it was replaced, but my OS on my Mac is really old and doesn't support the new one.

Also, I only used it once and don't really remember how it worked. Is there something explaining the basics?

Thanks!

SleepyHead still works. It is just not going to be developed further. There was a falling out between the original developer of SleepyHead (Mark Watkins I think), and some others that wanted to get involved.

Here is a link to the Beginner's Guide to SleepyHead. It should answer most basic questions.