This'll be a recurring series into 2013 and I'd like to first introduce Better Errors, which incidentally can be used outside of Rails as it simply hooks into the middleware of Rack apps.
group :development do gem "better_errors" gem "binding_of_caller" end
I've included the
binding_of_caller gem to allow using Better Errors' advanced features (REPL, local/instance variable inspection, pretty stack frame names) although, this is optional.
Next up, is RailsPanel and this is described by most quite simply as 'Wow'. It's a Chrome extension and gives the Chrome inspector insights into your Rails app... oooh!