Did you know Google is ranking websites differently these days? As of 21st April, if your website is not mobile friendly, it ranks worse than a site that is mobile friendly. You can read all about it at Google Webmaster Central Blog.
If you want to find out if your website is mobile friendly then head over to the Google Developers Mobile-friendly test and enter in your sites URL. It will do a quick analyses and give you a result.
I found a great website called MobileTest.me, which showed me what our website looks like on other mobile devices and tablets. One can test on an iPhone, HTC, Nokia Lumia, Samsung Galxy Y, iPad and the Google Nexus 7.
If you are running a WordPress website, there is a plugin called Jetpack, which has allows one to set up a mobile theme, thus making your website mobile friendly.