Exclude the cache from iCloud backup.

[laserjay]

I suspect XKCDY is including Cache Data within the iCloud Backup.

Therefore

• it uses a relatively large amount of iCloud data, which is quite limited with the free option (5GB)
• hence it creates more (mobile) traffic
• according to Apple Developer guidelines, reproduceable data shouldn't be included in the iCloud device Backup

Could you please consider changing that?

As I've briefly researched, there are quite a few possibilities, like

• storing the data inside a Cache folder, which should be automatically excluded from backing up
• using «NSURLIsExcludedFromBackupKey», see: https://developer.apple.com/documentation/foundation/nsurlisexcludedfrombackupkey
• using «isExcludedFromBackupKey», see: https://developer.apple.com/documentation/foundation/urlresourcekey/1408756-isexcludedfrombackupkey

What you could store though are favourites/liked comic strips, preferences and such. Then I suspect the backup size could shrink to Kilobytes or single digit Megabytes, instead of hundreds of Megabytes as it is right now.

[codetheweb]

How much is a large amount? It's using 75MB for me which is maybe slightly high, but Amazon uses around the same amount (as does WeChat, which I've never actually used).

Based on what I've read I'm not entirely convinced that cached images are being included. If you're able to download your backup and confirm that images are included I'm happy to debug further.

I think Realm (the database library) tends to create large blobs.

[laserjay]

My iPhone device backup is ~ 1GB in total, of which XKCDY takes up about 300 MB. Another app backing up cache data (offline maps) is approx. the same amount, so two apps of approx. 80 account for ~50% of backup data. All others seem to backup settings and smaller chunks only.

Do you have an idea how I could download my device backup to investigate further? As far as I'm aware, it's not easily visible within the iCloud folder structure. Only thing I can do on my Mac and iPhone when browsing the device backups from settings is to delete it and view the data amounts sorted by app.

[bbb651]

The app does indeed take up ~350MB in the worst case (I intentionally scrolled through all comics to make them available offline, would be nice to have as a feature):

But I think you're wrong about it being stored in iCloud backups, I've done a backup since and it barely takes up save at all:

[laserjay]

Then I suppose something is off with my installation. I might have to delete the local and iCloud data and re-download it from the App Store – even though that's going to delete my favourited comics.

In the meantime since I reported the issue I got another iPhone, therefore there isn't as much local data as previously stated:

However, the iCloud backup remains at almost 300 MB and is still the largest backed up app:

[laserjay]

I was able to reproduce the issue with a fresh install:

1. Delete the app from the iPhone and iCloud backup.
2. Re-download
3. Within a week of casual use, the app is ~50 MB
4. iCloud backup version is ~85 MB