No! Instant Agenda is designed as a real-time shared collaboration space. It works best when participants access the meeting as well as the person running the meeting. You can access it on a laptop, tablet, or phone. Instant Agenda works very for attendees on mobile devices.
If you are participating (not running the meeting), you do NOT need to create an account – you can join as a guest. Of course, you are welcome to create an account, which will give you access to any meetings you have joined in the past. That's useful because you can access the notes and action items from previous meeting sessions.
If you are running the meeting (as a facilitator) you need to sign up for an actual account.