seems you're trying to gather some pieces of information for your writing project and creating multiples of threads asking one question at a time In the different boards wouldn't help give you the compressed answer you're looking out for and doesn't speak well if you as a content writer.

There are a number of exchanges that accepts p2p NGN that you can easily get from your playstor if you're interested in carrying out a P2P transaction but because I don't completely know your intention for making this enquiry, it's best you use your Google search engine to get them as we aren't sure you're not working with our tireless Federal government who are looking for means to delist NGN from major exchanges and might just be  looking for existing ones to fight against.