Initially I was habituated with MI dialer. The app was smooth and very convenient to use. But in recent POCO phones, Google dialer is pre-installed. Most useless app I'd say. The 'record' option during a call remain in such a position that in most of the time mistakenly the button is pressed and the person on the other side feels his call is being recorded. Apart from thia, the 'mute' option is also an issue. I found no reason to separate 'Contacts' from 'Dialer'.