Really, why not use Skype? It is free, it is widely supported, it is convenient, it is already installed on lots of devices, users already know how to use it...
Do you know where a sensitive conversation is routed and stored?
Do you control the whole conversation?
Are you sure that all Skype messages, screen shares, file shares are encrypted throughout the channel?
Do you know if users' credentials and IP addresses are hidden from the outside world?
And especially: now, that scandals about user data sales and leaks are prominent (Facebook / Cambridge Analytica is just one of them), you have to ask yourself: "Nothing is free - what is the price of "free" solutions?"
KliP runs on IoChat servers located in available countries of your choice. Audio and video communication don't even use the IoChat server in most cases, they are established directly - user to user. Additionally, KliP serves two purposes - website communications and communications between internal users.