When Google first unveiled its new Inbox for Gmail
last Wednesday, it said that the new options for sorting your mail would be rolling out to Android and iOS "within the next few weeks". Well, Google decided to go on the early side of that timeframe, because we saw the Android update for Gmail
start rolling out yesterday, and today the update has hit the iTunes App Store.
As with the web and Android updates, this adds the new Inbox options to iOS which allows you to have your mail automatically sorted into categories: Primary, Social, Promotions, Updates, and Forums. The iOS app doesn't allow for customizing these categories (aka turning off the ones you don't need), so you will still have to go to the website to do that.
The iOS app has also gotten more granular control for notifications, so you can now choose to receive notifications for all messages, only important messages, or none at all, on a per account basis. And, these settings can be modified in-app.
If you want the update, Gmail for iOS is available for free in the iTunes App Store