Galaxy Ace 3 WhatsApp, Telegram & Viber Incoming Call

Testing WhatsApp, Telegram, & Viber incoming calls on my old Samsung Galaxy Ace 3 S7272 Duos. Now it runs LineageOS (CyanogenMod) based on Android 5.1. Galaxy Ace 3 S7272 is an entry-level cheap smartphone. Starting from 2016 it has been running CyanogenMod because its stock firmware started working bad. Chrome was too slow on it and there was a constant lack of free space because of the bloatware. Since 2017 I have been using this phone without GAPPS. Cause they started severely draining out the battery. That's why I have to install apps from .apk-files.