[antocv]

Ahem, not to sound like a pessimist.

Android 4.x has vpn, so one way to sniff data is to setup openvpn and on your server tcpdump or wireshark everything.

To sniff 3G/GSM I believe one would have to root their phone and sniff it there as most people dont have 3G/GSM hardware. I dont know more about that, perhaps its as "easy" as rooting it and running tcpdump on the device and saving to sd-card from some of its interfaces?