Synalyze It! is a simple-to-use OS X Hex Editor which will allow you to easily edit and analyze binary files of any size.
Synalyze It! features enhanced support for many character encodings and enables you to interactively define "grammars" for various file formats to speed up analysis and reduce manual decoding of files. Incremental search for strings and numbers, printing and other features make it a quite powerful tool.
Here are some key features of Synalyze It!
Note: This application contains in-app and/or external module purchases.