I got an email from ZYB mention that Vodafone have acquires their services on 16 May and still continue providing the services for free.
Vodafone* today announces that it has agreed to acquire 100% of ZYB, a privately-owned company based in Denmark which operates a social networking and online management tool enabling mobile phone users to back-up and share their handsets’ contact and calendar information online. The acquisition will be made for a cash consideration of Eur31.5 million.
I think they will have more features added in later after acquire by Vodafone.
Source : Vodafone