wondermill

If you want to graphically display a random list of your posts with their featured image in the side bar, then this is the plugin for you. This plugin allows you to set the category IDs (or all categories) you want to pull the random posts from, the number of random posts to display, the maximum width and height of the featured image thumbnail, the widget title, and the colors of the surrounding box.

Random Posts with Thumbnails

Puts a list of clickable random posts with their featured image in your sidebar as a widget, this list is customizable.

Paolo T. (pixline)

swergroup

NEW: <a href="http://blog.sucuri.net/?p=7654" rel="nofollow ugc">EXIF header malware/backdoor</a> sanitization!
Filenames on the web are different than those on the desktop. Empty spaces and strange characters doesn’t belong to web space. Enter UploadPlus: you can set your rules and clean your files’ name while they upload. Three basic rules:
<ul>
<li>keep only alphanumeric [A-Za-z] and digits, spaces and strange characters stripped out;</li>
<li>convert spaces and strange characters into dashes (-)</li>
<li>convert spaces and strange characters in underscores (_)</li>
</ul>
You can apply website-based or date-based prefix, even a custom prefix. Lowercase or Uppercase? Your choice! 
Some default prefix:
<ul>
<li>time/date based timestamps via PHP date()</li>
<li>blog name/slug</li>
<li>random</li>
<li>and many more!</li>
</ul>
UploadPlus can also transliterate filenames (text conversion from a non-latin script to raw latin characters). 
You can preview settings in the media settings page without uploading files.
<h4>Support</h4>
We’ll do our best to support the plugin on <a href="https://wordpress.org/support/plugin/page2cat">support forum</a>. Paid support and custom coding options are available on the <a href="https://swergroup.zendesk.com" rel="nofollow ugc">SWERgroup HelpDesk</a>.
If you found this plugin useful or need a new feature feel free to <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=CX6VQ6FVJFN4L" rel="nofollow ugc">sponsor a coding/support session</a>!
<h4>Credits</h4>
GPL2© 2008+ Paolo Tresso/<a href="http://swergroup.com/sviluppo/siti-internet-torino/" rel="nofollow ugc">SWERgroup</a>.

UploadPlus : File Name Cleaner

Clean file names and enhance security while uploading.

Random Posts with Thumbnails vs UploadPlus : File Name Cleaner