I ran into this program on my trip to China. If your phone can run QQ, it can most likely run this one as well.
http://weixin.qq.com/Really many different phones are supported.
Basicly this program allows you to speak, like a walkie talkie. You press the button, speak, release a button. And your voice gets sent to the receiver over the Internet. So it is a lot like talking on the phone, just free.
The voice files being sent are really small, so even if you have a small data plan with your phone company, its no problem. Watching a Y ou T ube video, or browsing the Internet on your phone will take up more of your Internet than this program in a month. (I pay 7 euros a month for my phones Internet)
So using this, to hear her voice every day is great. It also helps me to practice my Chinese, because I can actually speak a little with this program. Instead of just writing pinyin if I was using QQ. It also helps her to learn to speak, because she gets to speak and practice also. We can not use QQ every day to speak with each others and see each others. But we can speak with this program, so it is very valuable to us. Hearing her voice is so much better than just writing.
It is in Chinese, but I managed to install and use it anyway, and I did not understand a thing when going through the installation and settings. You sign in with your QQ number and password. But I can still use this software. Click on the persons name, a new window opens, then click on the speak button. And it works.
So if you know how to use QQ on your phone, you can use this one most likely as well. Or if you have a person who can read Chinese with you, can help to get this program and to use it.
Not too many Chinese people know of this program, I believe it is quite new. And I only saw it being used by young people.
Be warned, if you are not each savvy and don't understand Chinese language. This might not be for you.