harrym

WordPress uses phpass to store passwords. Because WordPress has to work everywere, it uses the portable version of phpass, 
which uses MD5 to hash passwords. MD5 is not a very good hashing algorithm for passwords, because it’s relatively fast.
This plugin switches over to bcrypt, which is the algorithm recommended by phpass, and is a much better option for password 
storage because it is much slower to produce. This makes it much harder for an attacker who’s managed to access your hashed 
passwords to obtain plain text passwords by brute-forcing, or by trying passwords from a dictionary.
Note: this plugin requires PHP 5.3.0 or newer
Be aware that if you use this plugin and then move to a host that does not support bcrypt, you will need to reset any user 
account that you want to log in with.

wp-bcrypt

wp bcrypt switches WordPress's password hashes from MD5 to bcrypt, making it harder for them to be brute-forced if they are leaked.

Fidgety Lizard

Kona Macphee

PLEASE NOTE: AS OF WP 5.7, THIS PLUGIN IS NO LONGER SUPPORTED.
Since WordPress 4.3, new users are no longer sent their passwords directly by email. Instead, they are sent a message containing a link to the Reset Password page, where they can choose their own password. Additionally, the Reset Password page now appears with a strong password already suggested in the “New password” field.
This plugin removes the suggested password from the Reset Password page, because often users assume that their password has already been set to this new suggested password (leading to repeated password reset requests, frustration and unnecessary helpdesk queries.)

No Suggested Password

AS OF WP 5.7, THIS PLUGIN IS NO LONGER SUPPORTED.
Clears the initial suggested password on the WP 4.3+ password reset page.

wp-bcrypt vs No Suggested Password