I've used Ultinous for the last 5 years. It has helped my company stay competitive in the market place. A real asset to my business. Ultinous supports many platforms and devices including smart phones, tablets and desktops. Very reliable and user friendly. Highly recommended. Ultinous does exactly what it says. They provide ultimatums to make sure your site works across all mobile devices and browsers. I like the fact that they use HTML5 as much as possible which means you don't lose any functionality when using an older browser. If you're looking for something solid and functional then check them out!