Trevor McKendrick has started a 10 post series about his path to launching a profitable niche iOS app, a Spanish Bible. His first two posts have been a very interesting take.
There’s something to be said about taking concepts that popular apps are using, and applying them to underserved niches. You won’t make millions, but it’s much easier to be in a low competition market where you can be a fast follower, emulating the concepts of others.
Beware though: don’t go niche hunting, find a problem you are interested in solving, or else you’ll get burned out quickly.