The following plugins are included with the FlatPress core distribution. There are also a lot plugins contributed by the community!

Plugin Name: Accessible Antispam

Description: Antispam asking to answer a simple math question.

Plugin Name: Admin Area

Description: AdminArea plugin.

Note: Provides Widget with some useful administration links and a login/logout link.
You must enable/disable it in Widget Panel.

Plugin Name: Akismet

Description: Integration with Akismet powerful Antispam system!

Note: Akismet checks your comments against the Akismet web service to see if they look like spam or not.
You must provide you personal API key by editing plugin.akismet.php. You can get an API key for free registering to http://wordpress.com/.

// change 0 into your API key
 
define('AKISMET_API_KEY', '0');
 
define('AKISMET_TIMEOUT', 10);

Plugin Name: Archives

Description: Adds an Archive widget element.

Note: Provides Widget with the entries' archive by months and years.
You must enable/disable it in Widget Panel.

Plugin Name: BBcode

Description: Allows you to use BBCode markup; provides automatic integration with lightbox. For additional information on BBCode see here.

Plugin Name: BlockParser

Description: This allow you to use simple non-plugin custom blocks

Plugin Name: Calendar

Description: Adds a Calendar widget element.

Note: Provides Widget with a calendar.
You must enable/disable it in Widget Panel.

Plugin Name: Categories

Description: Adds a Categories widget element.

Note: Provides Widget with a list of categories.
You must enable/disable it in Widget Panel.

Plugin Name: FavIcon

Description: Adds a global-wise (theme-independent) favicon to your blog; from a post on the forum

Plugin Name: jsUtils

Description: Provides mootools
This plugin has been recently replaced by jQuery.

Plugin Name: jQuery

Description: Provides jQuery

Plugin Name: Last Comments

Description: Adds a Last Comments widget element.

Note: Provides Widget with a list last comments.
You must enable/disable it in Widget Panel.

Plugin Name: Last Entries

Description: Adds a Last Entries widget element.

Note: Provides Widget with a list last entries.
You must enable/disable it in Widget Panel.

Plugin Name: Lightbox

Description: Lightbox overlays using slimbox.

Note: Requires Mootools (jsutils plugin). You must first enable jsutils!

Plugin Name: LightBox2

Description: Lightbox overlays using slimbox2.

Note: requires jQuery plugin. You must first enable jquery !

Plugin Name: PrettyURLs

Description: Url prettifier (powered by htaccess).

Note: Move the htaccess.txt file found to .htaccess in the root directory.

To upload I suggest creating a htaccess.txt locally with those contents, upload (via FTP) and then rename to .htaccess. Please notice that on apache+windows prettyurls won't work, because there's NO mod_rewrite support!

Plugin Name: QuickSpamFilter

Description: bans comments containing some special words; it can be customized editing the source file

Plugin Name: ReadMore

Description: Chops a lengthy entry and appends a “read more” link.

Note: to use it write the tag [more] somwehere in your text. This tag doen't require closing tag ([/more])

Plugin Name: Search Box

Description: Adds a Search Box widget element.

Note: Provides Widget with a search form.
You must enable/disable it in Widget Panel.

Plugin Name: Syntax Highlighter

Description: dp.SyntaxHighlighter 1.4.0 (edited to work with pre, thanks to Gert Thiel )

Plugin Name: Thumbnail

Description: If this is loaded, using the scale parameter on an image. The thumbnail is cached in the images/.thumbs directory. Remember that directory beginning with a dot are hidden on UNIX-like systems.

Note: to use it add scale=xx% attribute to [img] tag (e.g.: [img=images/something.jpg scale=50%])