This plugin will append CSS classes in default WordPress body class. You can get browser name, Operating System and actual device name.

Jose Mortellaro

Body Class By URL Parameter

It adds a CSS class to the body depending on the parameters included in the URL

ShinichiN

Add More Body Classes

Body tag with more classes such as locale and page slug.

syedkamruzzaman

Custom Class Add On Page

Add safely-prefixed custom  classes to Pages, Posts, CPTs, and WooCommerce views—no theme edits required.

Gourav RR

This plugin do best role to detect browser/platform. For wordpress developer its been complicated to detect browser/platform, this plugin will add browser/platform name as class in body tag of webpage, so as a developer you can easily detect browser/platform and write some CSS or JS stuff according to your requirements.
The plugin will do the following
<ol>
<li>
Browser
</li>
<li>
Web server
</li>
<li>
Device
</li>
<li>
Operating system
</li>
</ol>
For example, if you are using ipad, then this plugin will add ipad, osx, and safari classes in body tag.
<h3>Additional enhancements in version 2.0.0</h3>
<ol>
<li>
Detected browsers 
‣ Chrome 
‣ Safari 
‣ Netscape 
‣ Opera 
‣ Opera Mini 
‣ Opera Mobi 
‣ Mac Internet Explorer 
‣ Windows Internet Explorer 
‣ FireFox 
‣ Internet Explorer 
‣ Microsoft Edge Browser 
‣ Lynx Browser
</li>
<li>
Detected Web servers 
‣ Apache HTTP Server 
‣ Microsoft IIS 7 
‣ Microsoft IIS 
‣ Nginx Web Server
</li>
<li>
Detected Devices 
‣ iPad 
‣ iPod 
‣ iPhone 
‣ Android 
‣ Silk 
‣ Kindle 
‣ BlackBerry 
‣ Mobile
</li>
<li>
Detected Operating systems 
‣ Windows 10 
‣ Windows 8.1 
‣ Windows 8 
‣ Windows 7 
‣ Windows Vista 
‣ Windows XP 
‣ Windows 2000 
‣ Windows ME 
‣ Windows 98 
‣ Windows 95 
‣ Windows 3.11 
‣ Mac OS 10 
‣ Mac OS 9 
‣ Linux 
‣ Ubuntu 
‣ Mobile Web OS
</li>
</ol>
<h3>Arbitrary section</h3>

WP Browser/Platform Detection

For wordpress developer its been complicated to detect browser/platform, this plugin will add browser/platform name as class in body tag of webpage, so as a developer you can easily detect browser/platform and write some CSS or JS stuff according to your requirements.

Enjoy guys... :)

Alternatives to WP Browser/Platform Detection

Top alternatives