Apps such as Spotify, TikTok, Tinder and Waze were unusable for a few hours.
Angry users took to social media while DownDetector, which monitors net blackouts, reported widespread outages.
A similar issue happened in May, affecting services for part of a day.
Of this latest failure, Facebook said in a statement: "Earlier today, a code change triggered crashes for some iOS apps using the Facebook SDK [software developer kit]. We identified the issue quickly and resolved it. We apologise for any inconvenience."
The issues occur because app developers are encouraged to integrate the "login with Facebook" feature, in order for the social network to take advantage of the data the apps collect on users. It means that any updates will directly affect them.
The two incidents have led some to question whether Facebook has too much power over independent apps.
