Persival can persist the values users entered in forms, to make them resilient to inadvertent tab closing and crashes.
Asking persival to watch a form for changes and persist the values is really simple:
$("#form1").persival();
// You can give it an id if you have different forms in your pages.
$("#form1").persival( "firstForm" );
Once the form has been successfully submited, you can clear the persisted values:
$.clearPersival( "firstForm" );
Released under the MIT license.