Add offline mode to your app

POS has a very neat offline mode. It seems to be a good function to integrate into existing and new apps like production orders and hr?
Could someone direct me to code where this is and how it works?


Sales invoice in POS are saved in local storage when in offline mode, you can try to do the same for your app.

Please check the create_invoice method in pos.js

Actually I’m trying to create a small work log app which will pass task and time to timesheet.
I am only very new at programming. As this needs to works offline, I wanted to know best practice for this to sync with ERPNext.
Should I create a database locally and then sync directly to table in erpnext server?
or should is there some better way?