How to develop a iPhone application and make money off of it?

How can I develop a iPhone application and make money off of it?

To include after Michaels' answer learn xcode which is pretty native

Learn Objective-C and get comfortable with Xcode. As Android programmer myself I know there's about $30 one-time registration fee to open account under Google Play so I expect similar process with iTune Store.

After that, open ad account with someone to essentially sell off a banner placement to them, I recommend Google AdMob with iOS bindings; this is free, if you do wish to do a campaign that is different and do cost you further. Selling off apps direct to iProduct users would be a mistake.