AC Market is a third-party app store (not on Google Play) that provides modified APKs, cracked apps, and paid games for free. Version 3.2.3 is an older release — current versions are much higher (often 4.x or newer).
Just to give you a clear, helpful overview: Ac Market 3.2.3 For Android - Download
It looks like you're referencing an post for Android. AC Market is a third-party app store (not