MacOS Sierra is a free Tumblr theme which comes with a look that matches the MacOS desktop view with tabs opening. This theme supports all post types and displays them one above another, which you can close, minimize, maximize, and drag & drop on the screen. With this theme, you can easily use your custom colors for all the elements on the page. Not to mention, it is also possible to use custom images with this theme. This theme even supports high-resolution images and displays them elegantly without making them blurred. This theme works well on mobile and all other devices.