In a letter to developers, the company made clear that it would not tolerate "unhealthy behavior, like deceptive app names and spammy notifications."

Some of the changes seem obvious. Apps that disclose personal data without permission will no longer be permitted along with those that too closely resemble other apps and Android system apps in name or form. Anything that spams will be excluded.

"Products or the ads they contain also must not mimic functionality or warnings from the operating system or other applications," said Google.

"Developers must not divert users or provide links to any other site that mimics or passes itself off as another application or service. Apps must not have names or icons that appear confusingly similar to existing products, or to apps supplied with the device (such as Camera, Gallery or Messaging)."

Perhaps less obviously, the ads sometimes included in free apps will have to conform to the same standards as the app they are bundled with, which puts the onus on developers to coordinate this aspect of their software more carefully.