Do apps running on iOS 10 take up more storage space than on iOS 12? On my iPhone 6s Plus running iOS 10, the Clash Royale game app takes up 800 MB of space, but on my iPad mini 2 running iOS 12, it takes up only 190 MB.

The Clash Royale account on my iPhone is the same as on the iPad, so it has the same data in both, and I usually play it more on the iPad than on the iPhone. How come it takes more storage on my iPhone? Is it because my phone is running iOS 10?
Okay, so there might be a couple of reasons for this:


If your iPhone is below iOS 10.3, this difference may stem from the different file system format (Apple moved to APFS starting in iOS 10.3). This optimizes your app code size since APFS optimizes storage out of the box. See Here, Apple's Filesystem Documentation
Otherwise, it might simply because of the difference in handing the iPad and iPhone cases by the developer. There might be a multitude of reasons ranging from internal app data caching, internal testing to A/B testing of features.