BeerColors app for iPhone and iPad

Although its not as accurate as a spectrometer, using your eyes and a good quality color chart such as the one here, will let you evaluate a beers color. 
Function: BeerColors a reference for SRM and EBC color values.
Cost: none, no subscription fees or additional costs.
Privacy and Security: Data Collected – none. Access to address book, emails, etc. – none. Access to camera, microphone or location services – none. The app stores no data.
Help: The app should load and present user with a vertically scrolling list of colors. If it does not, delete and reinstall the app; there is no app data retained, so nothing is lost. A hard reset is suggested if that fails to work.