You could add a tunnel via iptables to just route one port on localhost to another ip
Not unpopular, just unrealistic. You can't do it on an iPhone, and if you're doing local web development you really ought to be checking it on an iPhone.
Broadly speaking, you want to test on the actual device your users are using, not an approximation of one.
Also... iphone?
> adb reverse tcp:3000 tcp:3000