THe one time we tried an app it was with a 3rd party developer that just did an HTML scrape of the page. Every single time we launched an update he had to put in an enormous amount of work just to make it work.
The site was never built with a public API in the back-end because frankly nobody did that shit in the early 2000s when most of the infrastructure was built.
We've had it on 'the list' for years to actually rip out the guts and re-build it with modern web infrastructure in mind, but its an enormous task that we haven't yet managed to get the time/funding to do.
The other option is to kind of re-build the site one chunk at a time, which is what we've been doing for the last few years. This works great, but has a lot of limitations compared to starting fresh, and things tend to take a lot longer than they should.
Believe me, as an avid iPhone user I understand the absolute god damn atrocity that is the mobile experience on NS. We've done our best to provide something that will hold people over until we can address properly, and doing so is very high up the priority list. Its going to be pandoras box though once we let the app floodgates open, so we need to make sure we do it right and address all the future demands of the codebase that will come with going there.
If we could raise like $200k through kickstarter we could easily re-build the site in 6-12 months with a team of fucking animals.