webvitaly

<ul>
<li><a href="http://web-profile.net/wordpress/plugins/" title="WordPress Pro plugins" rel="nofollow ugc">WordPress Pro plugins</a></li>
<li><a href="http://web-profile.net/wordpress/plugins/filenames-to-latin/" title="Plugin page" rel="nofollow ugc">Filenames to latin</a></li>
<li><a href="http://web-profile.net/donate/" title="Support the development" rel="nofollow ugc">Donate</a></li>
<li><a href="https://github.com/webvitalii/filenames-to-latin" title="Fork" rel="nofollow ugc">GitHub</a></li>
</ul>
Plugin sanitizes Cyrillic (Ukrainian, Russian, Belorussian), German, French, Polish, Spanish, Hungarian, Czech, Slovak, Greek, Swedish, Finnish, Latvian, Estonian, Mongolian, Bosnian, Croatian, Serbian, Montenegrin and other filenames to latin characters during upload. 
Plugin converts filenames to lowercase automatically.
<h4>List of sanitizing letters:</h4>
а б в г д е ж з и й к л м н о п р с т у ф х ц ч ш щ ь ю я ґ є і ї ё ы ъ э ў ą ć ę ł ń ó ś ź ż à á â ã ä å æ ç è é ê ë ì í î ï ð ñ ò ó ô õ ö × ø ù ú û ü ý þ ÿ ß ő ű ě š č ř ž ý á é ď ť ň ú ů α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ τ υ φ χ ψ ω ά έ ή ί ό ύ ώ ς ΐ ϊ ϋ ΰ đ.
<h4>Useful:</h4>
<ul>
<li><a href="https://wordpress.org/plugins/page-list/" title="list of pages with shortcodes" rel="ugc">“Page-list” – show list of pages with shortcodes</a></li>
<li><a href="https://wordpress.org/plugins/iframe/" title="embed content" rel="ugc">“Iframe” – embed content</a></li>
<li><a href="http://web-profile.net/wordpress/plugins/" title="WordPress Pro plugins" rel="nofollow ugc">WordPress Pro plugins</a></li>
</ul>

Filenames to latin

Sanitize filenames to latin during upload.

neoslab

MD5 Media Renamer will automatically rename and convert to lower case your media file during the upload process using PHP time() stamp as prefix and the file name encrypted in MD5() as suffix in order to keep your upload folder clean and organized. More information can be found at : <a href="http://www.natexim.com/wp-rename-file-during-upload/" rel="nofollow ugc">WP Rename file during upload</a>.
** Supported files Image extension **
<ul>
<li>.jpg</li>
<li>.jpeg</li>
<li>.png</li>
<li>.gif</li>
</ul>
** Supported files Document extension **
<ul>
<li>.pdf</li>
<li>.doc</li>
<li>.docx</li>
<li>.ppt </li>
<li>.pptx</li>
<li>.pps</li>
<li>.ppsx</li>
<li>.odt</li>
<li>.xls</li>
<li>.xlsx</li>
</ul>
** Supported files Audio extension **
<ul>
<li>.mp3</li>
<li>.m4a</li>
<li>.ogg</li>
<li>.wav</li>
</ul>
** Supported files Video extension **
<ul>
<li>.mp4</li>
<li>.m4v</li>
<li>.mov</li>
<li>.wmv</li>
<li>.avi</li>
<li>.mpg</li>
<li>.ogv</li>
<li>.3gp</li>
<li>.3g2</li>
</ul>

MD5 Media Renamer

Sanitize and rename automatically media files during upload using PHP time() as prefix and the file name encrypted in MD5() as suffix.

Filenames to latin vs MD5 Media Renamer