AppleInsider:

New developer guidelines released during WWDC set new rules for cryptocurrency apps distributed through both the iOS and Mac App Stores.

Apple has added new language to its App Store review guidelines related to cryptocurrency. Under the Hardware Compatibility section, Apple now states that “apps, including any third party advertisements displayed within them, may not run unrelated background processes, such as cryptocurrency mining.”

Good that they’re banning mining on the iOS device itself but not other aspects of cryptocurrency.