Hi Tian, You can use the Skype program with other Skype users for free. This includes audio, video and text chat, as well as sending files. If you buy some credits for Skype, you can also call telephone numbers at a low price. I often use Skype for international calls.

Hi Tan, unlike QQ you can't send offline files or audio messages. Both of the parties need to be online for data transfer. You can also try 3 or 4 party conversation. I wish you all the best.

we can use skype for make video call, chat, send voice message for free. you can install it on phones, PC, it's like WeChat. It'll be better if you try it.