>>It depends on the requirements for the App. If you need only the minimum for the Database, you can try SQLite instead of installing a whole SQL Server.
>>This is an example on how to use it https://blogs.msdn.microsoft.com/robertgreen/2012/11/13/using-sqlite-in-windows-8-store-apps/

>Thanks, I'll check it out. One of the requirements is to synchronise the data with a central SQL server database. Any idea of it can do that? I use ms sync >Framework for syncing.

Yes, I think It can be done:
https://jtabadero.wordpress.com/2013/01/09/synchronizing-winrtsqlite-using-sync-framework-toolkit/

And also check SSIS maybe it can help for the integration too.