File Converter

https://file-converter.org/index.html is a great tool for batch converting many files.

For example it converts Docs to PDF, movies, images, etc.

It supports a lot of different file formats:
Supported output formats Compatible input formats
Audio flac, aac, ogg, mp3, wav 3gp, aiff, ape, avi, bik, cda, flac, flv, m4a, mkv, mov, mp3, mp4, oga, ogg, wav, webm, wma, wmv
Video webm, mkv, mp4, ogv, avi, gif 3gp, avi, bik, flv, gif, m4v, mkv, mp4, mpeg, mov, ogv, webm, wmv
Image png, jpg, ico, webp bmp, exr, ico, jpg, jpeg, png, psd, svg, tiff, tga, webp, pdf, doc*, docx*, odt*, odp*, ods*, ppt*, pptx*, xls*, xlsx*
Document pdf doc*, docx*, odt*, odp*, ods*, ppt*, pptx*, xls*, xlsx*, bmp, exr, ico, jpg, jpeg, png, psd, svg, tiff, tga

It would be very nice to have it in PortableApps.