If you are not working in the same place as your colleagues, how do you communicate with them?

I prefer to use a messaging system with groups for the teams I belong to. When I can choose I use Telegram Messenger. It's available on all platforms, it's encrypted, it's easy to use and it's fast. I use it to communicate with my work and project groups, with my family, friends and relatives.

I also use the much hyped Slack. It's not my own choice, but the platform of the startup hub I work in. If I want to take part in those conversations I have to use Slack. It is definitely not my favorite. I find it messy compared to Telegram, but that's probably a habit issue.

How do you communicate?