Post Teaser generates excerpts of posts for the main, archive and category pages, also generate a word count, image count, and estimated reading time.
.../wp-content/plugins/post-teaserdirectory of your WordPress installation. NOTE: The issue with location sensitive installation have since been fix in version 3.11.3. The
post-teaser.phpfile is no longer restricted to the root of the plugins directory
Plugin Browser/Installerunder the "Get More Plugins" section at the bottom of the Plugins page in your WordPress admin panel (Yes, this page is found in your blog's admin page).
Post Teaser does not need to be configured in order to work but some users understandably wish to change settings. That's easy too -- the dead simple configuration page can be found under
Settings > Post Teaser (for version before 2.6
Options > Post Teaser) in your WordPress admin panel.