New “Custom Post Format" is here!
Flex is now with 8 post formats built-in for blogging: standard, video, gallery, audio, link, quote, status and new “Custom” post format. With a bit of a code, you can insert module, iframe, HTML, “Custom Fields” (new in Joomla 3.7) or “Shortcode” into your blog. Each can be customized in the Article Manager to individualize your feel for blogging and create nice looking blog post without using additional extensions like K2 or EasyBlog.
Also, in Flex template's admin, at the “Blog” section, you have now options to choose custom icons for Blog formats. If you leave the fields empty, it will show default (predefined) icons.