Sometimes I don understan WP core developers, and the extramly poor is_mobile() is a great example for something useless. Howdy WordPress! Who wanna see a big ios button on the Samsung Galaxy tablet?
So you need a better detection. And this plugin provides that.
This plugin is using php-mobile-detect, The lightweight PHP class for detecting mobile devices (including tablets) and I been using that script for a long time, outside the WordPress area.
I did some test of other plugins before I was going to develope my own, based on the script mention above. None actually filled the simpleness and stable of what I needed. Except for this one, Hmmm this might be a good solution - then I read that this was build on my old favorite script.
I only miss the auto class naming of each device setup like is-desktop class in the body tag, but ya can add easy your own function for that.
A tip, when using this kind of plugin, always make a if (function exsists) call, so your theme doesnt break when Not using mobile detection later on, for some reaason.