I can't get the 2 talk app to work properly on my iPhone 6 with iOS 9.2. It crashes every time I start it. I have uninstalled and installed, works fines on first go then crashes if I close and reopen it.
Gave the same issue in the wife's iPhone 5 with iOS 9.2.

Anyone else experiencing similar issues ? 2talk support still getting back to me on possible remedy.
Have installed zoiper in meanwhile but people on the other end complain of very low mic volum( struggle to hear us). I've installed the g.729 codec too. Any tips on best settings for zoiper to get best call quality?