Apple has said that it will publish the guidelines it uses to determine which programs it will sell in its App Store to appease critical developers.
The firm, known for its keen oversight of products, has been the subject of complaints from firms who have had apps blocked from the store.
Some developers have complained that the company's rules seem inconsistent.
Some have found apps blocked after seemingly minor updates, or for having content deemed inappropriate by Apple.
For example, the developer of Read it Later, an app that allows you to store web pages and read them offline, recently complained that Apple's reasons for rejecting an update to his app were "contradictory".
"For the first time we are publishing the App Store Review Guidelines to help developers understand how we review submitted apps," the firm said in a statement.
The introduction to the new guidelines - in theory only available to developers - outlines Apple's thinking about apps.
"We view apps different than books or songs, which we do not curate. If you want to criticise a religion, write a book. If you want to describe sex, write a book or a song, or create a medical app."
The firm also outlined certain types of apps that it would not accept.
"We don't need any more fart apps. If your app doesn't do something useful or provide some form of lasting entertainment, it may not be accepted."
The firm said it would also make changes to its licence that developers must sign to submit apps to the App Store.
"We have listened to our developers and taken much of their feedback to heart.
"Today we are making some important changes to our iOS Developer Program license... to relax some restrictions we put in place earlier this year."
Among the changes, the firm reversed an earlier decision to prevent developers from using tools that quickly translated code written for other products, into code designed to run on Apple devices.
At the time of the clampdown, Apple chief Steve Jobs said the tools could result in "sub-standard" applications.
The decision effectively blocked developers from using programs that software giant Adobe was about to release.
Following Mr Jobs decision and subsequent justification, Adobe CEO Shantanu Narayen hit back, calling Mr Jobs' words a "smokescreen".
He said the decision had made it "cumbersome" for developers who were forced to have "two workflows".
A spokesperson for Adobe said it was now "encouraged to see Apple lifting its restrictions on its licensing terms, giving developers the freedom to choose what tools they use to develop applications for Apple devices".
Jamie Lemon, a developer for Precedent, said that Apple may have relaxed the rules because of increased competition in the smartphone market.
"Apple has realised it is in competition with [Google's] Android," he told BBC News.
Recent figures from research firm Canalys suggest that shipments of Google Android phones increased 886% year-on-year from the second quarter of 2009. Apple showed 61% growth in the same period.
Mr Lemon said it would now be easier to develop for both Apple and Google's Android operating system.
"You don't have to plump for one or the other - it's easier to deploy your app across multiple platforms."