It was the "latest" stable release for ICS at the time, famously fixing a bug in Google’s backup mechanism found in previous versions. Compatibility: Android 4.0.3 and 4.0.4 ROMs. How It Was Installed
Because this package is from 2012, many of the apps within it (including the Play Store) may no longer function or connect to modern Google servers without significant manual updates or workarounds. Download gapps ics 20120429 signed zip
While original hosting sites like Goo.im are long gone, the file is still archived on repositories like SourceForge . It was the "latest" stable release for ICS