WordPress allows users to customize templates for web Pages but not so for blog Posts.
Post Template plug-in from IndiaNIC enables you to use the customized page templates for your blog posts also.
As soon as you install the Post Template plug-in, it appears on the sidebar of your page.
You can choose your desired template from the drop-down button and then you can view your Posts in that template.
* Note: No Child Theme support on this plug in at this time.
Also WP notes in October 2015 :
“This plugin hasn’t been updated in over 2 years. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.”