Big overview of what's missing in Safari 7.1+ and iOS 8+ in terms of browser storage.
Updated May 25th 2016
IndexedDB onupgradeneeded not firing correctly in Safari/iOS 8Fixed in iOS 9 IndexedDB transaction throw error for multiple object storeFixed in WebKit nightly! IndexedDB is deleting data when a PK is shared amongst two objectStoresfixed in iOS 9 IndexedDB array index keys are concated across cursor lifetimefixed in iOS 9 Add ObjectStore Blob Support for IndexedDBFixed in WebKit Nightly! indexeddb versionchange event not firedFixed in WebKit Nightly! IndexedDB does not throw ConstraintErrors for unique keysFixed in WebKit Nightly! IndexedDB openKeyCursor() returns primaryKeys in wrong orderFixed in WebKit Nightly! IndexedDB is not available in a web workerFixed in WebKit Nightly! window.indexedDB, IDBCursor and IDBKeyRange should be undefined when IndexedDB isn't availablefixed in iOS 9 WKWebView: openDatabase results in DOM Exception 18fixed in WebKit nightly! WKWebView: IndexedDB data doesn't survive an app relaunchbug in Cordova configuration, not WKWebView; see database-filler for working demo In home screen WebApps websql do not response after standyby under IOS 8fixed in iOS 8.2 openDatabase intermittently triggers SecurityError: DOM Exception 18 in Chrome on iOSfixed in latest Chrome regressed because of Chrome switching to WKWebView