APK MOD INFO
Name of Game: Stack
VERSION: 2.1

Name of the cheat, mod, or hack (credits: wendgames):
-UNLIMITED CURRENCY

Stack MOD APK 2.1 (Unlimited Currency)

Download the CACHE file/OBB file. They should be .zip or .rar files.
Extract the file to your sdcard.
Move the extracted folder to the location: /sdcard/Android/obb