Fame
Imagine it: There you are on your walrus-leather couch, sipping an iced chai latte topped with flakes of gold and reading about yourself in Time magazine. Yawn. You grab your iPad and guess what? You're trending. In your own app. Across the room, one of your three personal assistants is asking if you have time to be the keynote speaker at CES...but you don't because you're going to be too busy giving the keynote address at your own technology convention.
Now imagine this: There you are on your $10-off-Craigslist couch, sipping ten-hour-old coffee, and reading about your boss in Time magazine. Yawn. You've never even met the guy. You grab your off-brand tablet, give it fifteen minutes to boot, and open the app you've been working on for a few years.
The RSS news feed seems to be working better since you finished optimizing its code this afternoon. Across the room, one of your three angry cats is asking you if you have time to be the keynote speaker at CES...but you don't because you're hallucinating from sleep deprivation.
Both of these are possible. One of these is likely.
Yes, there's fame to be had as a mobile developer, but only once your work is so popular that people stop calling you "a developer" and start calling you by name. Can it happen? Yes. Will it happen? Let's just say...probably not.