Hacker News Reader

Best Practices for Developing Cellular Apps:

https://developer.apple.com/library/ios/documentation/Perfor...

Each of the network interfaces have different identifiers and you can get info about them.

Also maybe helpful, many of the apple BSD utilities have a `-C` and `-E` options to prevent binding to a cellular or "expensive" interfaces. For example, `netcat` has this, and is open sourced (part of Darwin), so you can poke around and see how they do it.

http://www.opensource.apple.com/source/netcat/netcat-22/netc...

(By the way, just bought the app - happy to pay $5 for this.. Good luck!)

Thanks!

In case you do decide you want to provide the option of downloading the whole thing, I would suggest bittorrent as the right tool for the job (basically it would avoid you having to pay most of the bandwidth cost).

Once you have tether detection you could create a favoriting feature, and locally cache those.