Mobile VoIP

Here is direct android version of mobilevoip download link if you have difficult to download via mobilevoip site.

IOS version of Mobilevoip is not available on the Apple store of China, you can download it from Apple store of USA.

To do that you need have an USA apple ID, you can buy one at TB. Alternatively you can download directly from Mobilevoip official site with old version

Another solution for IOS: You can use another app called MobiCall,This app functions the same as MobileVoip and is available in China Apple Store now, you can use current voip account to login on and use it, below is the link.
https://itunes.apple.com/us/app/mobicalls-cheap-calls/id635811447