This app makes money because anyone that owns a cat and an iPad looks for apps that their cat(s) can play with.
The same is true for baby apps. There are some super simple apps that babies enjoy, and those apps make very good money considering the development effort.
That being said, not everyone can pull it off. This particular cat app is fairly well done in my opinion. One must also keep in mind that just cause it makes $4k/month right now, it doesn't mean it'll continue to make that much 6 months from now.
I have two cats and it would NEVER have occurred to me to search for an app that my cats can play with. I am not a crazy cat woman and don't buy $1,000 cat toys. I mean, good on them for the success -- but I think anyone who actually stops and thinks "I wonder if there's a toy my cats can play with on my expensive electronic device" must be mental.
