The keenly awaited Snapper app for iPhone had 10,000 downloads in its first 48 hours, and was number one in the app store for free and travel apps in Wellington in that time.
As of Friday morning, the iOS app had more than 10,000 downloads, two days after its release at 10am on Wednesday.
The app finally allows iPhone users to top up their Snapper cards from their phones, something Android users had been able to do for several years.
Metlink general manager Scott Gallacher said Snapper's move into the iPhone market was a big step, giving all customers the option to top up on-the-go.
"We already offer android top ups so we now have a convenient service offering for most cellphone users," he said.