There are obviously a lot of examples of full fledged companies using their second mover advantage to become successful.The only example of and indieHacker-like business that copied another project that I was able to find is Software Engineering Daily. Jeff Meyerson said he copied SE-radio's format (with their blessing) and worked hard to make it 5x/week instead of 2x/month.
Have any IndieHackers had success copying another project?
I stumbled upon an image editor on Envato CodeCanyon a couple years ago and felt I could do better, it’s been going pretty well ;-)
someone from the UK copied Scott's Cheap Flights and made over a million.
Of course, I was too proud/moral to do that, haha