WordPress allows users to customise templates for web Pages but not so for blog Posts.
Post Template plug-in from IndiaNIC enables you to use the customised 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.

For the version available when we wrote this post : wp-post-template
For more support and updates Click here

* 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.”
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