Enough to sustain my modest lifestyle and put some aside for the future. But people with Silicon Valley salaries would probably laugh at my income. I have no boss, no investors, no employees to worry about. Just me and my ideas, on my own schedule.

I don't develop for iOS/Android, but from reading about others' experiences with phone apps, I think it's easier to find a small but steady market on the Mac. People will pay for useful Mac apps. And the Mac user market is more passionate and engaged with 3rd party software than phone users are.

But conversely, you are never going to strike it rich on the Mac with an "Angry Birds" type megasuccess. Mac app aren't sexy like that. (It's good, because the more developers are attracted to the glitz of iOS, the more they leave the Mac market for people like me...)

Numbers-wise, consider that there are are 1.9million apps in the iPhone App Store and 31,000 on the Mac App Store.