Like the stars of stage, screen and Sesame Street, the 25-year-old green tree frog called Godzilla​ was immediately ready for his croak up.

When Godzilla saw an iPhone at the Australian Museum this week, the male frog hugged it. It was an appropriate response given that a new smart phone app called FrogID is being described as an "urgent rescue mission" to save frogs that are vulnerable or endangered.

It's part of a national citizen science initiative to count Australia's frogs, which is being launched by the Australian Museum on Friday.

The app developed by IBM works a bit like the music identification and discovery app Shazam by recording male frog's chirps, barks and croaks. After downloading the app and turning on the location to aid identification, all users have to do is hit record when they think they hear a male frog calling out to attract the females of its species.