Geoffrey

Since WordPress 4.5, that feature is included in the Core. You don’t need this plugin anymore. Thank you all for support.
Adds the possibility for users to log in with its email address OR its username. 
Uses native WordPress functions. 
Lightweight plugin, no options, just activate it and it works!
Please, use the support forum to tell me bugs encountered, before rating the plugin. Be patient, it’s free, remember it 😉
Languages available:
<ul>
<li>Deutsch</li>
<li>English</li>
<li>French</li>
<li>Spanish</li>
<li>Russian</li>
</ul>
<h3>Other plugins</h3>
Find my plugins at <a href="https://profiles.wordpress.org/creativejuiz/" rel="nofollow ugc">https://profiles.wordpress.org/creativejuiz/</a>

Juiz User Log-in by email

Allows users log in with its email address OR its username

This plugin allows you to effectively hide your wp-login.php and wp-admin by requiring that you access it via a custom URL of your specification, with every other request being redirected to a different URL of your specification.

Unauthorised Login Redirect

This plugin allows you to effectively hide your wp-login.php and wp-admin by requiring that you access it via a custom URL.

Juiz User Log-in by email vs Unauthorised Login Redirect