For Crystal Clash players, this guide will provide all the codes i could find so far more will follow. You get free credits,hidden profilicon and secret achievements.
CODES
XXBX-R0F7-BR0K-3NG4-M3SX
XR0F-7ST3-4MC0-MMUN-1TYX
XXXX-XXXX-XXXX-XXXX-XXXX
XWVX-R0F7-D1SC-0RDX-UVXX
XXYX-R0F7-Y0UT-UB3X-YXXX
XXXX-R153-0FL3-G10N-5XXX
Codes found so far 6/8, more will be added soon
Referral Code: 9767235
Code: 4139332