The tech titan cited section 2.4.2 of its guidelines as its reason for removal. That section says apps should be able to "use power efficiently" and shouldn't "rapidly drain battery, generate excessive heat or put unnecessary strain on device resources." Miners are known to be quite resource intensive, so Apple could use the same reason to pull any other app that comes with crypto-mining features going forward. That is, if if it didn't only remove Calendar 2, because the miner it came with took things to another level.
Qbix originally introduced mining as an option for users who want to unlock the app's features for free. It was supposed to be completely opt in and was only supposed to use to 10 to 20 percent of a computer's resources. Unfortunately, a couple of bugs caused the Monero miner to go haywire. One of those bugs caused it to run indefinitely and to launch even without permission, while the other caused it to consume more resources than intended.
Magarshak told us Qbix earned $2,000 from mining within the three-day period that it was available. To make up for what happened, though, Qbix is using that money to improve its features. It's also making its premium features available for free for a whole year to everyone who's ever used the app. Yes, Calendar 2 is back on iTunes, and the developer is advising users to update their apps in order to remove the problematic version from their computers.