Do you know a self-sufficient softphone with cloud capabilities?

Question

Telephony

Hello!
I looked at the resources, questions go around the network, but I couldn’t find exactly the right option.
Requirements for the softphone:
1. Cloud synchronization of contacts and output to the identifier (it is desirable that it be possible to use either google contacts or other resources with the ability to synchronize contacts online)
2. The main platform of Windows and Ubuntu
3. Without a server part, only a self-sufficient client
4. Preferably with a Russian interface or the ability to make a translation file.

Answer 1

zooper? =)

Answer 2

hangout?

Answer 3

jitsi. SIP phone with translation file. You can use Google Contacts as a contact server (there is a plugin for Google).