What is their connection with Centrality, I can see then inter-connecting on twitter and other social media channels.

Sylo is part of Centrality's "Blockchain Family"

They're separate projects that work closely together.

Yea, watched an explainer video of Centrality. Glad to see Sylo has the support of such a strong project.

Sylo has been around for a much longer time. Their first Sylo release was 4 years ago and recently they have been focused on using decentralised blockchain technology available in their platform. This article might help you understand more about the goal of Sylo as a communication platform: https://medium.com/sylo-io/the-ground-we-play-on-74b3da110169?source=collection_home---2------0---------------------

I didn't know they are that old. I thought they released their application like last year?