Signal was mentioned yesterday on the news so I looked it up but wanted some opinions on it first before getting the app. I'm glad @Cumulus mentioned that the same developers worked on WhatsApp so that's reassuring.
I've heard of Telegram, I've never heard of Signal. I also have never used whatsup but I know a lot of people who have. To be honest I just use discord. Stopped using skype right around the time discord became popular though I was using skype for quite some time.