What does Apple consider to be tethering? I plan to create an app that connects an iphone with another device like a second iphone or a laptop. The problem with my app is that it will transfer data to and from these two connected devices. Some of the data that comes from the laptop will go to the internet and vice versa.

However all the data that is being transferred is very specific to the application. So the user can't simply use my app to surf the net and watch netflix. It's all restricted to the data from my application. 

Is this considered tethering? I have seen on many occasions tethering apps being pulled or rejected from the app store and I don't want that to happen to my app after spending a lot of effort developing it.
Apple implements tethering, so if your app proxies TCP/IP traffic directly, you will probably run afoul of several aspects of the review process.

Clearly, if your app is doing things to add value to the network you'll likely have more legs to stand on that your app isn't just the same implementation as carrier tethering:


linking IOT type devices
speak protocols other than just TCP/IP
allow filtering, reporting, proxy, QOS controls


Like all app submissions, your milage may vary. You can do the work and take your chances or you can line up a big customer and sell the app B2B style if you are worried about Apple deciding to pass on your app.