Currently we are using localStorage as persistent storage in our application. But we noticed that it is prone to data loss. Here is some links which supports this:
HTML5 Local Storage Not Persistent
http://www.sencha.com/forum/showthread.php?132952-localstorage-doesn-t-save-all-data
So now I'm searching for a new solution. It will be good if this solution is supported by chrome/safari at iOS/Android. Could someone suggest something?