Apple has tightened some of the rules in its
App Review Guidelines for Mac and iOS developers. Some of the new restrictions are meant to comply with the US government's revised Children's Online Privacy Protection Act. The law prevents collecting personal data from kids under 13 without parental consent; while the definition of personal data originally just meant names, locations, phone numbers, and physical and email addresses, this now also includes audio, photos, and video.
As an extra precaution, Apple is insisting that apps targeting kids have their own privacy policy, avoid tailoring ads to in-app activity, and avoid linking to outside content. Perhaps most significantly, the company demands that any in-app purchases have parental consent. The change may be a response to lawsuits and ongoing media coverage involving buying sprees by children, which in some cases have racked up hundreds or thousands on parents' credit cards.
Separately, Apple is exerting more control over gambling. In apps where people can gamble with real money, the app itself must be free to download, and remove any option to buy credits or real currency. In effect, an app can only support gambling with money if it serves an existing, external gambling system.