Snapchat has released an update to its disappearing-photo app following a security breach last week that exposed the phone numbers of millions of users.

And for the first time since the New Year's breach, the company said it's sorry.

Snapchat had promised a more secure version of its app following the breach, which allowed hackers to collect the usernames and phone numbers of 4.6 million of its users.

The Los Angeles startup on Thursday released an update to its Android and iPhone apps that it says "improves Find Friends functionality." The feature, which suggests Snapchat connections based on a user's phone contacts, was at the heart of the breach. Users can now also avoid linking their usernames with phone numbers.