rafacesar

This plugin makes the themes upgrade easy to the user. Using the admin upgrade messages and system.

WP Theme Update

This plugin helps to make a theme easier upgradable.

Gary Pendergast

Advanced Automatic Updates adds extra options to WordPress’ built-in Automatic Updates feature. On top of security updates, it also supports installing major releases, plugins, themes, or even regular SVN checkouts!
If you’re working on a WordPress Multisite install, it will properly restrict the options page to your Network Admin.
While this will be useful for the vast majority of sites, please exercise caution, particularly if you have any custom themes or plugins running on your site.

Advanced Automatic Updates

Nice Plugin

Adds extra options to WordPress' built-in Automatic Updates feature.

WP Theme Update vs Advanced Automatic Updates