Google has introduced a significant update to its Play Store Developer Policies and in so doing banned more categories of apps. For example, apps that mine cryptocurrencies on Android devices are no longer allowed. "The only cryptocurrency mining apps allowed are those that mine outside of the device, like cloud-based mining," said Google in the updated policies. Apps that copy other apps are now banned, as well. Google is specifically seeking to keep apps that steal the user interface or content from original apps out of the Play Store, as well as apps that are "created by an automated tool, wizard service, or based on templates." Google has put new safeguards in place to keep apps that "facilitate the sale of explosives, firearms, ammunition, or certain firearms accessories" from the Play Store. Apps that offer how-to instructions on creating bombs, guns, ammunition, and other weapons are prohibited. Last, apps that "appeal to children but contain adult themes" are no longer welcome in the Play Store. Google is banning apps that look to trick users by impersonating other people, companies, or businesses. The new policies went into effect immediately. Developers should ensure their apps meet the new criteria when submitting them to the Play Store.