So it is still a messenger or a utility for a messenger?
And the coins will be used for encryption-I understand correctly?
an interesting concept -I have not heard of such

As far as I've understood Sylo and used it, it's a communication platform similar to WeChat but with future decentralization no one will see the data exchanged expect you and the receiver (no way to steal, modify or corrupt the data). As for the token, it will be used inside the application ecosystem for transactions, more storage, and DApp usage.
Exactly, that's the main goal of Sylo. They provide decentralized communications through P2P technology and by utilising blockchain nodes so that the service won't be down. This is the easiest I can explain it to you, maybe reading the whitepaper might help a bit.