Storage options for win 8/10 universal app?

Assuming I want to develop a Win 8/10 universal app eg calendar, the user has a two devices tablet/phone.

How can my calendar share a local SQL database?

I don't want to maintain or administer an azure service or any other remote DB service ie AWS, VPS running SQL Express etc.. which is overkill for such a basic scenario.

I have considered SQLite and dumping the DB file in the users MS OneDrive folder but as we know this could result in sync/lock issues.

So using a purely self contained & free model, how can my two devices share this basic SQL data?