Calendar 2, a third-party replacement for Apple’s free Mac application Calendar, has disappeared from the App Store after adding an option that let users mine cryptocurrency to unlock premium features. Following user complaints and a story by Ars Technica, developer Qbix said that it would remove the mining option from “future versions of the app,” initially keeping Calendar 2 in the Store. However, the app has since vanished, leaving it unclear whether the mining feature violated the App Store’s terms.
The concept of utilizing untapped computing resources for cryptocurrency mining has been controversial, as the benefit of compensating software developers without using cash has been undermined by the performance hits mining places on devices. In recent months, Cisco and Adblock Plus have fought against surreptitious cryptocurrency mining installations by hackers, while Monetizr and Aura have sought to use either cryptocurrency or a computer’s mining resources to pay for in-app content.
Until Calendar 2, the Mac App Store had not featured an app with a cryptocurrency unlock option. But Qbix’s app included the xmr-stak Monero miner, which last year was deployed by The Pirate Bay to unwittingly turn site visitors into miners. By comparison, Calendar 2 didn’t attempt to hide the mining functionality. Qbix showed it in a Preferences menu and said that it would start mining only if the user enabled the feature, selecting it over a recurring 99 cent monthly charge or $17.99 one-time fee for “all new and future” features.
Qbix responded after user complaints that the miner was turning itself on and consuming more computing resources than the developer anticipated. Apparently, the miner was supposed to devote only 10-20 percent of a machine’s power to mining, but instead was taking at least 40 percent, perhaps more. Qbix cited energy waste, an inability to quickly fix the issue, and the mining’s unintended automatic start as reasons the feature would be pulled, saying that Qbix would “get out of the ‘mining business’ ” altogether.
Apple has not responded to inquiries regarding whether an app with a cryptocurrency mining feature was in violation of App Store guidelines. Similarly, Qbix has not said whether it or Apple was responsible for removing Calendar 2 from the Mac App Store. We’ve reached out to the developer for further comment and will update this article if we hear back.