I used to chat regularly with my brother through Skype. Skype was difficult to load. Then I tried imo app in which the picture quality was not good and it used to come a bit distorted. Then I searched the internet and found Google duo and it was absolutely the perfect chat app which I wanted. In duo, there is no concept of type chat. It’s all about video chat the interface is very easy to use. On opening u get a icon to video call n chose contact who u want to call. The picture quality is very good and the app size is also small. Very good chat app.