iOS 9 was released a couple days ago, and it has many unsung heroes. My favorite of these is “Wi-Fi Assist”.

Several versions of iOS ago — specifically in a iOS 6 beta, the option for “Wi-Fi Plus Cellular” was briefly trialed. It disappeared by the time iOS 6 came out, and was conspicuously absent from iOS 7 and iOS 8.

In iOS 9, “Wi-Fi Plus Cellular” rose from the ashes, as “Wi-Fi Assist”.

Wi-Fi Assist allows for your phone to more aggressively fall back to using its onboard cellular connection in case the Wi-Fi it is connected to doesn’t respond in a timely fashion. While dangerous for some with small data plans, for those with some breathing room, this is a fantastic addition.

To disable it (it’s on by default), go to Settings > Cellular > Wi-Fi Assist. It’s way at the bottom of the Cellular settings screen, almost hiding. Unfortunately, this setting doesn’t appear in the new-for-iOS-9 search within the Settings app.

As someone with a grandfathered unlimited data plan, I find Wi-Fi Assist hugely useful. I noticed its utility the first day I had iOS 9 installed.

Every day, when I leave work, I send my wife a text with my ETA. I do so using the wonderful Workflow app. However, I do so as I’m walking downstairs from my third floor office. During that walk, my phone hasn’t yet realized that it can’t reach my office’s Wi-Fi anymore. In iOS 8, I would have to use Control Center to toggle Wi-Fi off in order for Workflow to get a response from Apple Maps with the driving time to home.

Now, with iOS 9 and Wi-Fi Assist, my phone is able to figure things out all on its own.

A small win, for sure, but a welcome one.