Answer a survey in offline or server down. Check that you see a sync button. Check that clicking the sync button in offline/server down shows an error. Go back online or turn server up and click synchronize. Check that answers have been stored. Answer another survey in offline. Before synchronizing, go to Moodle web and answer it in there. Now go back in the app and click sync in online. Check that you see a message telling that offline answers have been deleted. Finally, answer another survey in offline, go back online and wait for sync to trigger (could take more than 10 minutes). Check that answers are automatically sent.