In order to allow people to better use the service while suggestions are still being made to improve it, add the ability to add custom categories, with custom fields.
Obviously, username and password are two required fields, and would certainly help the system work better, but until the product is fully fleshed out, custom categories with custom fields is a great mid-point.
Hypervault team could probably also use it to add the most popular custom categories if they’re doing data mining on their clients.