Apple has updated its App Store Review Guidelines, which explains to developers what an app may and may not do. Though the updated Guidelines have many small changes, the two sections that saw the biggest revisions were for apps aimed at gamblers and children.
Gambling apps that offer real money gaming may not offer players credit via in-app purchases. Also, all gambling games must be free. From the new Guidelines:
20.5 Apps that offer real money gaming (e.g. sports betting, poker, casino games, horse racing) must have necessary licensing and permissions in the locations where the App is used, must be restricted to those locations, and must be free on the App Store
20.6 Apps that use IAP to purchase credit or currency to use in conjunction with real money gaming will be rejected
Guidelines for children's apps have been revised to more closely comply with the federal Children's Online Privacy Protection Act (COPPA) as well as Apple's push to make iTunes Store accounts available to those under 13 in iOS 7. COPPA has always restricted developers from collecting a minor's name, address and telephone number, but now the law also says it's illegal for developers to collect data like photographs, video and audio.
17.3 Apps may ask for date of birth (or use other age-gating mechanisms) only for the purpose of complying with applicable children's privacy statutes, but must include some useful functionality or entertainment value regardless of the user's age
17.4 Apps that collect, transmit, or have the capability to share personal information (e.g. name, address, email, location, photos, videos, drawings, persistent identifiers, the ability to chat, or other personal data) from a minor must comply with applicable children's privacy statutes.