This module needs a new maintainer
They won't make Notifications go faster, it will be actually a bit slower when used on a single web server. Though for bigger deployments it can really increase troughput by using drush workers instead of cron and distributing the workload.
Different modules provide logging, queue processing with drush, multiple worker threads with Drupal Queue, and some other options for fine tuning composition and message sending background processing.
IMPORTANT: There are no new features here, just some tools to manage high loads of Notifications and Messages. If your site is working fine without these modules, you don't need them.
Set up instructions are in the module's README.txt