Really waiting for matrix to add native group video calls without jitsi
> The Signal Protocol's development was started by Trevor Perrin and Moxie Marlinspike (Open Whisper Systems) in 2013.
From the WhatsApp Wikipedia page:
> After months at beta stage, [WhatsApp] launched in November 2009, exclusively on the App Store for the iPhone.
From my own experience, I was on WhatsApp back in 2009-2010 on my OG iPhone that I got as a hand-me-down from a friend who’d just upgraded to the 3G/3GS.
So the branding and history of WhatsApp is longer, but the core is Signal. Also if you used both apps and their desktop clients you can easily see how close these two are.
The front end, however, remains significantly better on WhatsApp than on Signal.
I continue to use both daily, and as much as I loathe Facebook, I still prefer the UX on WhatsApp way more than Signal. That they look similar is more down to the fact that messengers today all look the same (look at facebook messenger, iMessage) than that WhatsApp has taken Signal's front end. If anything, Signal is slowly trying to emulate WhatsApp features, in a more privacy-preserving way, which understandably takes time.
There are other of these style apps too, but fluffy is furthest along I think. https://matrix.org/clients/