Here's a way to get iphone 4 hotspot working on n7. Tried and tested (But not by me

). And it only works with pdanet
1) Get a working copy of pdanet (Paid or from your usual friendly source)
2) Activate it. Select wifi hotspot and set your SSID, wep key
3) Install Busybox and ZT-180 adhoc switcher on the n7. Download links here :
http://115.com/file/aqag50mo#
4) Install busybox. You will see a "Install" bar at the bottom. Tap on it, after that when "Status

one", exit.
5) Next is ZT-180 adhoc switcher. Install, run.. the screen will go blank for 5 secs. When the "try to switch to ad-hoc mode, just to try..." appears that only can you configure SSID/WEP settings
6) Press Continue — Continue —Settings — Select SSID for Adhoc mode then key in your iPhone's PdaNet SSID and under Set Wep Key in your Wep Key
7) Lastly, select the "try to switch to ad-hoc mode, just to try..." button. You will be able to connect to your Iphone's hotspot with the N7.