Hi, I have an S3 phone with data connection through sim card and a little portable router with data connection through sim card too and it can share the its connection through wifi. I'm looking for an app to switch my phone in default on Wifi when its cellular data connection is on 3G (the portable router); but when it is on 2G or no data I wish the phone switchs on 3G data cellular on phone if it's available? Do you know something? I hope anyway this post will be an urge for developers!!!