Ko Takagi

This plugin allows you to update the password for the post or page at a time.
Manage your protected passwords easier.
<h4>Related Links</h4>
<ul>
<li><a href="https://github.com/ko31/replace-protected-password" rel="nofollow ugc">Github</a></li>
</ul>

Replace Protected Password

This plugin allows you to update the password for the post or page at a time.

KaeruCT

This plugin allows passwords for password-protected pages/posts to be passed directly through the URL.
The query string parameter that should contain the password is <code>pw</code>.
For example, if the URL of your post is <code>http://myblog.com/password-protected-page/</code> and the password is <code>PASSWORD</code>, 
then just append <code>?pw=PASSWORD</code> to it.
If the URL already contains a query string (for example, <code>http://myblog.com/?p=5</code>), then be sure to append <code>&pw=PASSWORD</code> instead.

Password Passthrough

This plugin allows passwords for password-protected pages/posts to be passed directly through the URL.

Replace Protected Password vs Password Passthrough