This achievement can be found on the Crystal Clash Facebook page
https://www.facebook.com/CrunchyLeafGames or by searching for Crystal Clash on Facebook. You can also click the in-game Facebook button in the main menu to bring you to the page.
To unlock this achievement head over to the shop in-game. Click on redeem bonus code and then copy and paste or type out in all caps in the box. Once done hit enter for an achievement.
XUVX-R0F7-F4C3-B00K-XVUX