Mobile synchronization pattern


Does anybody use synchronization pattern developing meteor mobile app?
The target is to get mobile app which can work offline and synchronize data when connection established. Mobile app and web are meteor applications.
To make app standalone I plan to use ground:db.
But how you organize data synchronization?
I have seen several ways.

  1. Create subscription on Meteor.connect
    But how to deal with conflicts resolution?
  2. Create own api(REST for example)
  3. Use existing solution(if any, maybe some services)

Does anybody deal with such problem?