Welcome to Coller 2.0. Its a Major Upgrade over the Old Coller Theme. This new one comes with many powerful Features, more customization options and what not. Everything you need from a theme is there. Plus, it loads terribly fast. And Yes, its Fully Responsive on all devices from smallets phones to bigger desktops. NOTE: Coller 2.0 Is a Major Upgrade, where it switches from Theme Options to WordPress Customizer.
This theme is made by inkhive