From John Narun:
OS X utility for renaming and renumbering sequences of files within a folder. Features include: filter source files by name, number, or type; optional copy; set new filename prefix, number of digits in file number, and starting number; strip or change file extension; set sort order to numeric, alphabetical, by date, or by size; supports drag and drop.
What's new in this version:
Improvements for processing large lists of files: optimized code and improved user feedback. If you frequently use File Sequencer for lists of files longer than 50, this is a must have upgrade for you.