Yes. I am an indie iPhone app publisher in the health & fitness space and I earn a healthy 6 figures working ~25 hours a week.

I’m hoping to crack 7 figures in the next couple of years.

I made almost nothing the first 4 years writing apps but eventually learned the craft. I have lost as much as $30,000 on a single dud app and probably had 5 failures before any success.

I highly recommend M.J. DeMarco’s book - Millionaire Fastlane and I’m a big Tim Ferriss/4 Hour Workweek fan.