JohnnyPea

This plugin adds registration date and last login date columns on the “Users” page. 
It also checks whether user logs in within 30 days after the registration if he does not his account is deleted – this option is disabled by default, you can change this settings on Check Last Login Settings page in Settings menu.
WARNING! The plugin is not updating the login time when logging through stored login cookies.
I am open to suggestions to improve the plugin !

Check Last Login

Simple plugin which checks user's login status and displays registration date and last login date columns on the "Users" page.

Chad Butler

This plugin is a password generator that creates random passwords with using words, numbers, and special characters.
Default random passwords can be difficult to for users to use (and remember – if they don’t change it). WordPass simplifies this process by using words to create passwords. Passwords will be generated in the style of 2*Kayak29, 2Bigcranium2#, or %36POTATOE6.
This plugin works with WordPress as well as with any plugin that uses the WordPress password generation function.
WordPass allows you to create a custom list of words to be used in password generation.
The plugin will create random passwords from your word list and apply numbers as well as capitalization. How these settings are applied can be set in the plugin’s settings. The recommended setting is “random” for best security.
Note: this plugin is great for membership sites where subscribers or low level users need easy to remember passwords. But you should use secure (and possibly more complex) passwords for higher level users, especially administrators. Use common sense in the application of this plugin!

WordPass

Creates word-based passwords for WordPress.

Check Last Login vs WordPass