Update 21/12 - Service is unavailable from 4 am to 7 am (GMT).
There will be a regular update for new features and bug fixes, so the game service will be temporaily closed from 4 am (GMT) for up to 3 hours on Dec 21st.
1. Google Play Game Service for Android users is now available.
2. Apple Game Center for iOS users is now available.
3. Google Play Game Service now provides achievement contents.
4. Many bugs are fixed.
Contact firstname.lastname@example.org if you have any problems in the service.