Apple has revised its standards for developers regarding cryptocurrency mining, according to a report by AppleInsider. The company has updated two separate sections of its App Store Review Guidelines.
Section 2.4.2 of Hardware Compatibility now states, "Design your app to use power efficiently. Apps should not rapidly drain battery, generate excessive heat, or put unnecessary strain on device resources. Apps, including any third party advertisements displayed within them, may not run unrelated background processes, such as cryptocurrency mining."
In March 2018, 9to5Mac reported that Apple pulled a calendar app from its App Store for violating the efficient power guidelines. It appears that the app, Calendar 2, had implemented a Monero miner as an alternative to a paid service or advertising-based business model. Over the course of three days, the team behind Calendar 2 apparently earned approximately $2,000 worth of Monero before the app was removed by Apple.
Apple has also updated section 3.1.5(b), which is specific to cryptocurrencies. The revised guidelines introduced subpoint (ii), which instructs that "Apps may not mine for cryptocurrencies unless the processing is performed off device (e.g. cloud-based mining)."
Apple's tough stance on mining is probably for the best. The updated standards should help protect App Store users and ensure the longevity of Apple devices.
Note: Apps for trading cryptocurrencies and tracking prices will not be affected by the changes.