You've been able to check in via your mobile for a Virgin flight for quite a while, but you still had to then print out a pass when you hit the airport and the option only worked between Brisbane, Melbourne and Sydney. From today, passengers will be able to check in using their smartphone for flights from all mainline ports and receive a boarding pass which can be scanned at the gate.
Jetstar has had a similar option since May last year, which works with any SMS-capable phone. Virgin's offering is slightly more restricted: you need a smartphone (since it sends a QR code link), and it won't be operational at the Gold Coast for a few months. (It also won't work for international flights, though given check-in and passport requirements that's no surprise.) As with online check-in, the option opens 24 hours before flights.
Virgin has also launched a flight specials app which highlights current specials and lets users sign up to receive alerts for specific routes. Right now it's iOS-only, but Virgin says an Android version will appear later this year.