In short, no.
Attendee accounts (as well as guests) can join meetings, add topics, and view meeting results. Attendee accounts are free of charge. This makes it very easy for meeting participants to use Instant Agenda without commitment or extensive sign-up process.
A trial or paid Moderator account allows you to create and run an unlimited number of Instant Agenda meetings. Moderators can take notes, create action items and send meeting summaries.