Not exactly sure, what you are asking for, more details would be appreciated and so this is my best guess.
You are telling, you have the ability to identify a niche product by the problem they solve and so you are asking if there are other platforms which do that?
AFAIK, needgap i.e. this platform is the only platform which gives importance to problems. Products which solve those problems are listed in the threads and those who face the problem themselves try it out fulfilling the whole cycle. There are several products being created for the problems posted here and many of which are of niche category.