This sunsetting of support has profound implications for any device running KitKat. Once the authentication protocols changed on Google's servers, older versions of the Play Store and Play Services could no longer communicate. This prevents users from signing into their Google accounts, downloading new apps, or even updating existing ones.

Where to get APKs (safety tips):

A user with an Android 4.4 device (e.g., Samsung Galaxy S5, Nexus 5, or older budget phones) is seeking the latest Google Play Store APK that their aging OS can still run.