In fact, to communicate with friends, you can choose any popular instant messengers, including Viber, Skype or WhatsApp, but nonetheless the most popular is Telegram. I almost constantly use WhatsApp to communicate specifically with people I know personally, and Telegram is used to communicate with people I met in games and on the forum. But Telegram is practically a messenger for scammers and therefore you need to be careful, especially when it comes to gambling or making money.
Yes, that's one issue with telegram. There's so many scammers that are using it as their place because using it is easy and there's not that much verification needed to use.
As long as you don't talk to strangers, you'll be fine since you just have to talk to your gambling buddies.