Complete the following tasks to unlock Apple Game Center achievements.

Achievement	How to unlock
1 Quadruple Stamp	Stamp 4 boxes at the same time with 1 stamp. Do this 1 time.
10 Stamp Streak	Stamp 10 times in a row without missing.
10 Stamps 1 Box	Stamp 10 times in the same box.
20 Double Stamps	Stamp 2 boxes at the same time with 1 stamp. Do this 20 times.
3 Triple Stamps	Stamp 3 boxes at the same time with 1 stamp. Do this 3 times.
30 Stamp Streak	Stamp 30 times in a row without missing.
5 Stamps 1 Box	Stamp 5 times in the same box.
50 Stamp Streak	Stamp 50 times in a row without missing.
8 Stamps 1 Box	Stamp 8 times in the same box.