Since I don't have all the devices & iOS versions available at hand, it's difficult to understand some of the issues my client is experiencing on older devices (namely iPad 1 and 2, both running iOS 5 [unsure of minor version]).
Is there any documentation on how each of the iOSes respond to a webapp reaching it's cache size limit? (5MB supposedly? or I could be wrong, might just apply to the Web SQL Database size)
Also is the cache size limit the same across all devices & iOS versions?
Note: the issue my client is having is right at the beginning, it's showing up the page as if Javascript was disabled (I've sent a message to ask if that's the case). But in the event they haven't manually disabled it, could it be that Javascript is automatically disabled specifically on the webapp because the limit was exceeded?
As far as limits goes, there is a long list of tests conducted by suburbia.org.uk using the browserstack.com tool.
It covers more than just the iOS devices (Android, Windows phones, Desktop OSes, Chrome, Firefox, Opera, etc.)
http://suburbia.org.uk/appcache_limit_tests/html5_application_cache_device_storage_limits-jan_2014.pdf
Here's a preview of the iOS tests, where each columns represent:
Browser Version | OS Platform | Device | Default maximum | Maximum (with prompts)