ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
CONV. - Convert YouTube video to MP3, GIF or MP4
Ralpha Image Resizer - High-speed image batch conversion tool
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
Yout - YouTube to Mp3 Converter