It's been a constant bone of contention for app developers worldwide, what exactly does Apple look for when it's deciding on an application's suitability for official distribution? Or, more likely, why has Apple turned down an app?

Obviously, sauciness or violence are two points that stick in Steve Jobs' craw, but those are merely the most obvious barriers for the Apple stamp of approval. Many other apps have been turned away, often with confusing reasoning.

Therefore, Apple is to publish its official App Store Review Guidelines; a document that reveals each part of the process undertaken before accepting an app or not. It will list all the dos and don'ts for developers and programmers when creating Apple device-compatible software.

"For the first time we are publishing the App Store Review Guidelines to help developers understand how we review submitted apps," says the Apple press website. "We hope it will make us more transparent and help our developers create even more successful apps for the App Store".

Additionally, the company is relaxing certain developers' restrictions to help the creation process: "In particular, we are relaxing all restrictions on the development tools used to create iOS apps, as long as the resulting apps do not download any code. This should give developers the flexibility they want, while preserving the security we need".

So far, there are over 250,000 apps available, and iTunes has been host to 6.5billion app downloads. The App Store has given out over $1 billion in royalties to developers.

Are you a developer who has has an app turned down? If so, let us know more in the comments below...