Sharaz Shahid

Code Widget is simple widget allows you to insert any arbitrary Text/HTML and run PHP Code or Short Code. This Widget parses PHP code into simple text and much more.
Only users with the unfiltered_html role will be allowed to insert unfiltered HTML. This includes PHP code, so users without admin or editor permissions will not be able to use this to execute code, even if they have widget editing permissions. 
This plugin is developed and maintained by <a href="https://twitter.com/sharazghouri1" rel="nofollow ugc">Sharaz Shahid</a>

Code Widget

Code widget help  to  add  Short Code, PHP Code, HTML, and Simple Text in widget.

Tanmoy

The normal Text widget allows you to insert arbitrary Text and/or HTML code. 
This allows that too, but also parses any inserted Shortcode and PHP code and executes smoothly.
All Shortcode must be enclosed in the standard [ and ] tags for it to be 
recognized. 
All PHP code must be enclosed in the standard tags for it to be 
recognized.

WP Sidebar Essential

Like the Text widget, but also allows working PHP code and shortcode to be inserted.

Code Widget vs WP Sidebar Essential