NibUnlocker is a free Mac OS X application that can parse and output a non-editable nib file as an editable xib file. The xib file created by NibUnlocker does not contain all the information from the original nib file, but can be useful for examining the nib file's structure.
Blinged JSON Validator is a free app to validate JSON files with syntax highlighting, whitespace indentation, error messaging, and hotkeys.
