Unable to find install package

I've followed the install instructions for Komento, but everytime I've tried to install via Joomla installer, I keep getting the error message "Unable to find install package." So I figure I'll upload it via FTP and install from folder. I unpack the file and put it in my tmp directory and I still get the same error message. Is there a folder where the install package is located within the zip file which I need to extract? Please advise.

Thanks,