Alexandru Vornicescu

This is a WordPress plugin that will add a fullscreen button functionality to your Text Widget editor.
After you press the fullscreen button the editor will take all free space of your screen.
Now you can view and inspect your text easier.

Text Widget Fullscreen

This is a WordPress plugin that will add a fullscreen button inside your Text Widget.

Shambhu Patnaik

Pro Text Widget plugin.You have choice to text widget show only specific Post/category/Page.
<h4>Features :</h4>
<ol>
<li>You have choice to specific to widget show only posts/pages/categories.</li>
<li>Multiple post/category/page option(comma separated).</li>
</ol>
More detail : http://socialcms.wordpress.com/

Pro Text Widget

Pro Text Widget plugin.You have choice to text widget show only specific Post/category/Page.

Text Widget Fullscreen vs Pro Text Widget