Mullenweg had accused Apple of cutting off the ability to update the app to get its 30 per cent fee on the App Store, and the Internet erupted in the favour of a platform that lets people build and manage websites and blogs for free, and also sells domain names.
Apple backed off, "issuing a rare on-the-record apology," reports The Verge.
"We believe the issue with the WordPress app has been resolved. Since the developer removed the display of their service payment options from the app, it is now a free stand-alone app and does not have to offer in-app purchases," Apple said in a statement on Saturday.
"We have informed the developer and apologise for any confusion that we have caused," it added.
The WordPress founder welcomed the move.
"I am very grateful that folks at Apple re-reviewed @WordPressiOS and have let us know we do not need to implement in-app purchases to be able to continue to update the app. Bad news travels faster than good, usually, so please consider sharing that they reversed course," he tweeted on Sunday.
"We will continue to be responsive and do our best to be within both the spirit and letter of the app store rules, including closing any webview loopholes that pop up. This also made me appreciate the freedom of the open and independent web".
Mullenweg earlier accused Apple of cutting off the ability to update the app to get its 30 per cent fee on the App Store.
"Heads up on why @WordPressiOS updates have been absent... we were locked by App Store," he tweeted.
Apple charges App developers 30 per cent fee on purchases on its App Store but WordPress does not sell anything.
"My life's mission, and the purpose of WordPress, is to increase the freedom of the internet. I hope in addition to native apps people continue to create websites and web apps that provide accessibility, autonomy, and freedom to the widest audience," Mullenweg said.
Apple is currently involved in a legal batter with Fortnite developer Epic Games in a similar manner.
Top news publishers have joined Epic Games that has filed a lawsuit against Apple.
Apple on Friday hit back at Epic Games for filing a lawsuit against its App Store policies, saying the Fortnite game developer has created its own problems and Epics actions are putting the "entire App Store model at risk".