[ZenFone] Can I use Smart volume on 3rd party apps?
Yes, volume adjustment can also be applied to 3rd party VoIP (Voice over IP) apps which support Wi-Fi Calling and VoLTE (Voice over LTE – 4G LTE), such as WhatsApp, Line, Wechat, Messenger, QQ, etc.
To enable this feature, go to Settings > Sounds & vibration > Smart volume > Internet calling apps.
Note: This knowledge is currently only applicable for ZenFone 6. Please stay tuned for further updates on ASUS Official Website.