Skeptical that anyone is actually making millions on fart apps, I checked and see that people are actually buying fart apps. I didn't see any that had enough installs to break 5 figures, but still, there's some money to be made with silly app ideas. In general, I wouldn't consider app development as a get-rich plan. Some people may strike gold, but your average app developer is struggling to get pennies from ad revenue and many paid apps may make enough money that it might justify the time to build. To me, I think the safest assumption to make with app development, is that you're building a sellable skill. Other people that think they can make millions from their app idea will happily pay you a very high hourly rate to build their app, so you get steady income without the risk.