The Facebook iOS app received consistent criticism for its lagging performance and failures to update notifications consistently. Earlier in 2012, Facebook said that an update would arrive around June 2012. Although two months late, the social network delivered an update no longer based on HTML5 while completely overhauling the app's performance.

Facebook claims that the new iOS app is twice as fast as the previous version.

"We've rebuilt the app from the ground up, so now the app opens much faster and the news feed and notifications load right when you open Facebook," Facebook iOS Product Manager Mick Johnson said. The notable change for users may be notifications. Messages sent to a user will appear near instantly, rather than not appearing at all on the previous version of Facebook.

CNET described the new app as bringing a "noticeable faster overall experience" along with improvement to the iPad app. UI improvements include an indication of how many news stories there are, and redesigned buttons to post a status update, for example.

It is a marked change to the reaction to the old Facebook iOS app: it had a 2-out-of-5-stars rating on the App Store. Previously, users even preferred the mobile Facebook website before the performance-improving update, and the site will continue to be based on HTML5.

Facebook is also investing in an engineering team in London, the first outside of the U.S. Investors have criticized the social network for not bringing in revenue from the apps despite the increasing usage of the desktop website. Vice President for Engineering for Facebook, Mike Schroepfer, admitted Facebook is seeing a "huge change".

Whether Facebook may feel the need to charge for the mobile apps, or introduce advertising into the experience, is unknown. Facebook's app was free from launch.

Facebook for iOS is available to download now for free. Minor updates also arrived for the Android version.