is anyone port this app for N9?

It's a distro, not an app. It could be run in a chroot, but some of the tools will not work because the n9(50) wifi drivers lack packet injection support.

so N9/50 cant inject like N900 ? or lxp working on a new drivers ?

Correct me if I'm wrong here (wasn't part of this at the time), but my understanding is this development came with financial background, should be possible for N9 (especially as most people assume N9 numbers are far greater at this point than N900 ever achieved, I'd say disputable), throw in 10$, 1/10th of N9 users should be enough to hire a guy full time for a couple of months. Reverse engineering this driver should not be much harder than N900. Finding the right guy for this and not someone who'll say working on this, here is donate button... might be much harder. Low level arm programmers who can reverse engineer drivers are extremely hard to come by and have spare time at the same time

yes, i need this app badly.

its not an app, its a distribution. Just get a small laptop and install it there.

a few of the tools are ported and working, what is missing is packet injection and NAT modules for iptables.
look in my signature for tools that have been ported.

yes applications that BackTrack includes can be ported, but not the Distribution as such, at least if you don't want to use exploits to get chrooted (or use openmode).

if you dont know what backtrack is then why you need it