It’s been just over three months since Instagram copied Snapchat stories and slapped them on top of its feed. The move appears to be a success: within a few weeks, 100 million people were using the feature every day. (Snapchat’s entire app gets 150 million users a day.) Instagram stories are almost identical to the Snapchat version, but they have an extremely useful extra feature: you can rewind them by tapping on the left side of the story. Well today it’s Snapchat’s turn to copy: you can now rewind stories just as you can on Instagram.

The feature is part of an update to Snapchat that also includes “world lenses,” the rear-facing camera version of the app’s famous selfie filters. And like most updates to Snapchat, the feature is totally hidden. But when you update to the latest version, you’ll notice that you can tap the left side of any snap to return to the previous snap.

It turns out to be an essential feature for browsing stories, since we often tap through them at lightning speed. Until now, to view a snap in Snapchat again you had to exit the main story feed and either search for your friend’s name or scroll all the way to the bottom and find them in the alphabet. In retrospect this was insane, but as of today it’s no longer the case.

One other hidden feature in today’s app: you can now send a snap from a friend’s story to another friend. Until now you could only share from the Discover feed; now your friends’ drunken antics are fair game as well. Just tap and hold their snap to bring up the share screen.