Lightly edited question from a reader -

i'm working on iphone apps whilst in my day job, until the income from that can replace my day job, then i can resign and start a business where i'll make ipad apps for [small business], and one day hope to take that to [large businesses] where i'd love to slash the red-tape bureaucratic burden, and make things better.

Read this -

http://www.sebastianmarshall.com/inventors-who-want-to-do-business-stop-doing-build-first-because-it-doesnt-work

I'd recommend you write a letter outlining your iPad services idea, and send it to 100 [people in that particular industry] you respect. Offer to do the first one for relatively cheap, perhaps $10k USD, half upfront, half on completion. Be willing to outsource/pay well and make almost no margin on the first one just to do it. And then you'll be in the business you want. Waiting is so, so linear.

These might be relevant too -

http://www.sebastianmarshall.com/my-approach-to-business

I hate linear thinking. I mean that with no disrespect. But the world is so linear, and doesn't have to be. If you want to make doctor's apps, start pitching doctors right now. There's really no good reason to wait, if you're sure you care about it and like the work.