This module is intended to be used as an APC opcode cache flush automator for high performance Drupal-setups.
If you have setup PHP with apc.stat=0 in production and you deploy code updates (with version control or CI or whatever) you need to either restart your webserver or restart php-fpm to flush the opcode cache. You could also execute apc_clear_cache() with a script.
This task becomes more complicated when you have multiple webfronts. All servers need to flush in sync - or they will execute different code, which will mess up everything. Also, doing webserver restarts theorically might abrupt current http requests, while apc_clear_cache() doesn't.
How to use
This module integrates with standard Drupal cache clear and drush. To flush caches (for one or more servers) with drush, you can run:
drush cc all or drush cc apc
When to use
This module is useless for you, unless you have configured your production PHP server(s) with apc.stat=0!
Code deployments to production should usually/always end up with a global cache clear, and the cache clear integration makes things work mostly out of the box. There are some special cases such as when the site is in maintenance mode, but those challenges can be circumvented.
Why to use