Uninstalling Backbone
You can uninstall Backbone Work Sync from your instance by going to the manage app section. When you uninstall Backbone from your instance, the following will happen:
The sync panel on the work items synced will be removed
Updates between the previously synced work items will no longer be synced
The work items synced will not be deleted (Backbone never deletes any work items )
Reinstalling Backbone
If you reinstall the app within 180 days, then all your synchronization still exists and you can start the synchronization where you left off.