It's definitely Telegram. Nearly everybody has downloaded it on their mobile phones. People can chat with the one they love for free as long as they have WiFi.
I often use the social apps like Telegram, or the entertaining apps like NetEase cloud music. I use them either for socializing or for entertaining, you know, searching for fun and relaxing myself.
No. Most of the old people don't like to accept new things. And they find apps very complicated and far beyond their abilities. So they won't try using apps.
I'm not quite addicted to technology, honestly speaking. I think there are all kinds of apps right now, apps for learning, studying, exercising and financing, etc. It's more than enough for me. But I do think that the apps should be much simpler, so the older generations can use them too.
The first app I used··· it was around high school when I had my first mobile phone, I guess it was Viber, a social app. It was popular at that time, and I had different kinds of groups. However, it seems that Viber was replaced by Telegram because of limited functions. But I won't forget the happy hours it brought to me.