Please excuse the abridged instructions. Feel free to ask questions via e-mail until they can be improved.
RepetitionFinder is a utility for finding repetition in files. It is most flexible for text files, but can be used for binary files too. To use it, simply open a document or paste text into the input box at the top, then click 'Find Repetition'. By default, it is configured for finding repeated text at the "whole word or longer" level.
Many of the options are self-explanatory. Some are explained in the sample text. Please give it a try, and e-mail for advice if you are having trouble getting the results you want.
A brief list of the less obvious features follows: