Yesterday an app showed up on the iPhone Application Store called “NetShare.” NetShare, which is a product of Nullriver, is a SOCKS proxy which let’s your Laptop connect to your iPhone over WiFi and share its EDGE or 3G Internet connection.

This arrangement is typically called tethering. It is a common feature with a lot of other phones. You are supposed to pay $30 or so on top of your standard data plan to use it, though a lot of people get away with using it with basic data plans. There is no tethering plan for the iPhone.

It was a little suprising to see such an app on the application store. So, it wasn’t much of a suprise when it registered as unavailable a few hours later.

Then it showed up again this afternoon, before disappearing again. I managed to snag a copy before it vanished again. It seems to work pretty much as promised.

I don’t know what is going on. One of nullriver’s other apps, Tuner, which plays streaming audio, had a similar on-again-off again presence early in it’s existance, but it has been solidly available for a while.

My theory is that this is just a glitch, and that Apple let the product through on the first place because they aren’t ready with their own tethering app. I think a later version of the firmware will bring tethering and the opportunity to give AT&T even more more money every month. As a consolation, AT&T will finally turn on free wifi at their Hotspota for iPhone owners with an appropriate data plan.

Yeah yeah yeah. I know, it’s a lame theory but at least I did it in a fee thousand fewer words than Cringley would have spent on it.