Why is the same app a different size on iPhone 7 Plus vs iPhone 6?

[FundyKayak]

My wife and I are sitting side by side downloading our app updates over wifi. I'm on an iPhone 7 Plus, she has an iPhone 6. My Facebook (v.)98.0 update is 369 MB while hers is 237 MB. What? Her Facebook Messenger 124.0 is 147 MB while mine is 254 MB.
What accounts for the difference? We are both using iOS 10.3.2. The version numbers of the apps match.
So why are my downloads bigger? Something to do with the 7 Plus vs 6? But what?
You can see the app size in MB just next to the app icon in the App Store>Updates window.

 

[carolineM]

There may be some correlation with the size of screen. You have more real estate and will incidentally use more data.

 

[FundyKayak]

There may be some correlation with the size of screen. You have more real estate and will incidentally use more data.

I can see that while using the app. But the app itself? That would imply that the app downloads all the interface screen sizes specific to the model? I didn't think app downloads were that complex. No "one size fits all"

 

[carolineM]

Apps can "stretched" or scaled up using special coding, which could lead to an increase in size.

 

[FundyKayak]

Apps can "stretched" or scaled up using special coding, which could lead to an increase in size.

Isn't that stretching and scaling done "on the fly" at the time a screen is called up for display?

 

[carolineM]

This is where we need to call an expert!

 

[zstairlessone]

Used to be the correct sized images were included in the os, I assume it is still so. The scaling that occurs is to the image loaded on the phone so a higher pixel count screen will have a significantly larger file size if there are a lot of images and operating systems, apps, and the like are loaded with high quality images to give you the best experience possible. .

 

[FundyKayak]

Used to be the correct sized images were included in the os, I assume it is still so. The scaling that occurs is to the image loaded on the phone so a higher pixel count screen will have a significantly larger file size if there are a lot of images and operating systems, apps, and the like are loaded with high quality images to give you the best experience possible. .

There's a difference between the physical size of the app being downloaded from the App Store and the amount of memory it uses while in use on the device. I can understand that the larger images would take more space to be drawn during use. But let's say someone posted a 1024x768 image on Facebook, the amount of memory to download the image to view on a regular sized device compared to a plus size or an iPad would all be the same 1024x768px.

So, the images required to make the standard size and Plus size interface images would both be included within the app. Universal apps would also include iPad Mini, and iPad and the newer larger iPads. To accommodate all the different sizes the more elaborate photo-based pages in the interface would be the biggest memory drain, not to mention included ads.

A lot of the interface differences are just the width of dynamically resizing header bars and text handled by the iOS.

So if images for all the device sizes are all included inside the app package why does the app turn out a different size on the regular size compared to the Plus size? A different size at the time of download implies that the App Store is changing the content of the app to suit the target device. Otherwise the app developer would have to provide a different version of the app for each different device size.

 

[scifan57]

A while back, Apple implemented a process called app thinning which is designed to optimize storage space on your device by only downloading the files your specific device needs, resulting in a smaller size app on your device as it doesn’t have to contain the code for all the other iOS devices. This may explain what you’ve noticed between your wife’s iPhone and your own.
://arstechnica.com/apple/2015/06/app-thinning-will-be-a-major-boon-for-8gb-and-16gb-iphones-and-ipads/

 

[zstairlessone]

^^ exactly, and why a higher pixel screened iOS device has a larger file size - larger images embedded = larger file size

 

[FundyKayak]

A while back, Apple implemented a process called app thinning which is designed to optimize storage space on your device by only downloading the files your specific device needs, resulting in a smaller size app on your device as it doesn’t have to contain the code for all the other iOS devices. This may explain what you’ve noticed between your wife’s iPhone and your own.
://arstechnica.com/apple/2015/06/app-thinning-will-be-a-major-boon-for-8gb-and-16gb-iphones-and-ipads/

That's what I was looking for. Thanks.

 

[FundyKayak]

A while back, Apple implemented a process called app thinning which is designed to optimize storage space on your device by only downloading the files your specific device needs, resulting in a smaller size app on your device as it doesn’t have to contain the code for all the other iOS devices. This may explain what you’ve noticed between your wife’s iPhone and your own.
://arstechnica.com/apple/2015/06/app-thinning-will-be-a-major-boon-for-8gb-and-16gb-iphones-and-ipads/

And that's why when I restored my new 7Plus from my iPhone 6 backup it insisted on reloading every app from the App Store and using up most of my month's data.

 

[scifan57]

That's what I was looking for. Thanks.

You’re welcome.