iPhone and iPad
The browser on the iPod touch, iPhone, and iPad is Mobile Safari. Per Apple's App Store Review Guidelines, all other web browsers that run on iOS and iPadOS wrap the same system WebKit library as Safari. This means they have the same deficiencies in support for web platform features as Safari, no more, no less.
- This is outdated
Despite iOS 1.0 touting Safari as the primary programming interface for the original iPhone, it took several years for Safari to gain support for key web platform features.
I checked for how big a web app could be (tried Google
mobile safari offline limit), and it appears to be limited to 5 MB. The localStorage object is likewise limited to 5 MB (tried Google
mobile safari localstorage limit).
Even accelerometer support wasn't added until iOS 4.2.
- JNCF, 2019-07-20