Here is the full list of all 13 ClearMem :: Free Up Your RAM Now achievements.
Congratulations! You're now a ClearMem user!
You've cleared up this much RAM: 50MB
You've cleared up this much RAM: 100 MB
You've cleared up this much RAM: 250MB
You've cleared up this much RAM: 500 MB
You've cleared up this much RAM: 1 GB
You've cleared up this much RAM: 2 GB
You've cleared up this much RAM: 3 GB
You've cleared up this much RAM: 4 GB
You've cleared up this much RAM: 5 GB
You've cleared up this much RAM: 6 GB
You've cleared up this much RAM: 7 GB
You've cleared up this much RAM: 8 GB