NBS for G Suite has a few advantages, such as;
(1) You can manage accessible users to the app.
(2) Centrally manage assets with single spreadsheet for multiple users
Your G Suite super admin requires to install the app on your G Suite domain. If you want to use the app with multiple users, it's best to choose G Suite accounts as the app log each users activities.
NBS for personal gmail:
If you don't need above features but just want a single person utilize the app, the easiest way is to create a personal gmail for your project(ie. email@example.com) and share credentials with folks who need to use. NBS works with multiple devices simultaneously.