Aquí tienes uno muy bueno que instalamos a un cliente y funciona perfectamente mediante pop-up
HTML
<div class="container">
<h1>Popup Login & Signup with jQuery</h1>
<a id="modal_trigger" href="#modal" class="btn">Click here to Login or register</a>
<div id="modal" class="popupContainer" style="display:none;">
<header class="popupHeader">
<span class="header_title">Login</span>
<span class="modal_close"><i class="fa fa-times"></i></span>
</header>
<section class="popupBody">
<!-- Social Login -->
<div class="social_login">
<div class="">
<form>
<label>Full Name</label>
<input type="text" />
<br />
<label>Email Address</label>
<input type="email" />
<br />
<label>Password</label>
<input type="password" />
<br />
<div class="checkbox">
<input id="send_updates" type="checkbox" />
<label for="send_updates">Send me occasional email updates</label>
</div>
<div class="action_btns">
<div class="one_half"><a href="#" class="btn back_btn"><i class="fa fa-angle-double-left"></i> Back</a></div>
<div class="one_half last"><a href="#" class="btn btn_red">Register</a></div>
</div>
</form>
</div>
</section>
</div>
</div>