With the release of iOS 11 earlier today, Apple has announced that it has increased the cellular over-the-air app download limit to 150MB from 100MB.
This means that you can download apps and updates from the App Store over a cellular connection. If the apps or updates are more than 150MB then you would need to download it by connecting to a Wi-Fi network.
Higher Limit for Over-the-Air Downloads
We’ve increased the cellular download limit from 100 MB to 150 MB, letting customers download more apps from the App Store over their cellular network.
When Apple first launched the App Store, the cellular over-the-air app download limit was 20MB, which was increased to 50MB in March 2012. It increased the cellular over-the-air app download limit to 100MB again in September 2013. So it has been quite a while since Apple increased the limit.
So if you have enabled automatic download of updates from the App Store, then you may want to revisit the decision as this could lead to an increase in mobile data usage.
Meanwhile, users with unlimited data plans would have preferred the ability to remove this restriction.