Am looking to build an app that would function like google keep. just a light brush of the features:
Chrome app with offline storage - save online when internet is available
Android app and ios that would sync with the web server and also update locally and online -single user
Am thinking that I would have a bridge(SERVER) of some sort to handle the imports and exports of data between different platforms. Thus emulate a sync.
Keep uses IndexedDB as it is the standard datastore available to Chrome Apps. You should be able to right-click on the screen and see the code (visit the Resources tab).
Chrome Apps also has Synchronised Storage that will manage offline and cloud access to your data storage. This means you can set a key on one machine the user has and see it updated immediately on the other machine of the user. The problem is that if you as a developer want to access and manage this data you can't do it, which is why Keep chose to use IndexedDB and manage the synchronisation themselves.