Answers
What is the difference between Naven and WhatsApp?
WhatsApp is end-to-end encrypted and requires a phone number. Naven is not encrypted end-to-end and requires no phone number — it screens messages before they send, which is only possible because it can read them.
These are opposite ends of one trade. WhatsApp's encryption means nobody, including WhatsApp, can read your messages, and therefore nobody can screen them. Naven's screening means messages are checked against twelve published categories before delivery, and therefore the server reads them.
WhatsApp is also ubiquitous, which is a real advantage: the people you want to talk to are already there.
The phone number is the other difference. A WhatsApp group hands every member's number to every other member, permanently. Naven groups involve no phone numbers in either direction.