Flexo is a free Tumblr blog theme that has been created using flexbox. This theme features a perfectly responsive design that can be browsed without any interruption over any device. Not to mention, this theme also supports Disqus comments, which you can set up on the blog and get into constant discussions with your readers. You can also show your latest tweets using this theme. This theme also comes with the group blog supportability feature. You can also use this theme to display high definition images without blur effect. If you are looking for a highly flexible and modern Tumblr theme to show any post type elegantly, this theme has got you covered.