Apple's iOS 9.3 beta introduces major new features like Night Shift , but there are also dozens of little tweaks to be discovered in the operating system update. It appears that one of those minor changes applies to Wi-Fi Assist, adding a much-needed feature that allows users to see just how much data it's using.Wi-Fi Assist data usage can be checked within the Settings app by choosing the Cellular section and scrolling down to the Wi-Fi Assist option. Next to the toggle that turns the feature on and off, there's now a data usage number that displays how much data has been consumed when it is in use.Wi-Fi Assist was first introduced with iOS 9. It's a feature that allows an iPhone to seamlessly switch over to a cellular connection whenever a local Wi-Fi connection is weak. Enabled automatically when updating to iOS 9, Wi-Fi Assist proved to be unpopular with users who claimed it was eating up a lot of data . One recent news story even accused Wi-Fi Assist of causing a teenager to receive a cell phone bill for upwards of $2,000.Concerns about Wi-Fi Assist led Apple to publish a support document on the feature, explaining how it works and assuring users that data usage should only be a "small percentage higher" than previous usage. Wi-Fi Assist only turns on in a limited number of circumstances and won't activate when data roaming, when apps are downloading background content, or when using third-party apps that stream audio or video.Despite Apple's reassurances about Wi-Fi Assist, unhappy customers filed a $5 million class action lawsuit over the feature, with the plaintiffs claiming they were subjected to overage charges on their iPhones after updating to iOS 9. The lawsuit also claims Apple did not do an adequate job explaining the feature when iOS 9 was released.Wi-Fi Assist is available on any iOS device running iOS 9 or later, with the exception of the iPhone 4s, the iPad 2, the third-generation iPad, and the original iPad mini. Wi-Fi Assist can be turned off using the Settings app for those who don't want to risk using extra data.