JamPot is releasing an app that allows you to make and update an app straight from your iPhone. Sounds pretty cool, but will undoubtedly result in sucky apps. Plus, you need a £25/month subscription package!! http://www.bbc.co.uk/news/uk-northern-ireland-15075450
I've actually heard of quite a few of these development environments in the works, the problem always seems to be the Apple approval process.
