iOS App Help

Yesterday, I downloaded mine control for my server and iPhone. I got it working perfectly and love it. Today, I tried accessing minecontrol via 3G on my iPhone and I can't connect to my server. I left minecontrol and the server running on my PC. When I am connected to my home wifi which the server is running off of, minecontrol iOS works excellently. Am I doing something wrong? On the iOS app the server ip I have entered is my private ip. I have also tried my public ip and that didnt work either. Any tips on what I can try?

On the setup screen, there's an area for setting up external IP addresses. You can use that to enter your external IP and port and see if it's accessible from the Internet. You have to make sure you have your IP and port forwarded through your router. There's some more info here about port forwarding if you need it.