You've commented at least 3 times pushing this service. From their home page:
> We charge a small fee to enter your Jabber ID and phone number into our directory. This cross financing allows us to make Quicksy completely free for its users. If you are a paying customer of the conversations.im hosting service, you can enter your number for free.
As stated on their home page, it's a fork of the Conversations (conversations.im) client with contact discovery which they're selling.
> Quicksy is a spin-off of the popular Jabber/XMPP client Conversations with automatic contact discovery.
So it's just a conversations.im client trying to make a buck with a contacts service based on what I can see. Edit: in context in case you didn't know, Matrix (at least via app.element.io -> vector.im) has a contact discovery service, and it already works with phone numbers and email addresses using a blind one-way lookup for privacy.
> We charge a small fee to enter your Jabber ID and phone number into our directory. This cross financing allows us to make Quicksy completely free for its users. If you are a paying customer of the conversations.im hosting service, you can enter your number for free.
As stated on their home page, it's a fork of the Conversations (conversations.im) client with contact discovery which they're selling.
> Quicksy is a spin-off of the popular Jabber/XMPP client Conversations with automatic contact discovery.
So it's just a conversations.im client trying to make a buck with a contacts service based on what I can see. Edit: in context in case you didn't know, Matrix (at least via app.element.io -> vector.im) has a contact discovery service, and it already works with phone numbers and email addresses using a blind one-way lookup for privacy.