Thanks for your question.
i-Attend Mobile Capture is $55/mo for unlimited number of devices. Two iphones, 10 tablets, 50 ipads, etc - we do not have a limit.
We defined user accounts as administrators and mobile uses - we also do not have a limit on the number of admins you want to create.
You will need to subscribe to one of plans (Platinum, Enterprise or Unlimited) in order to use the mobile app or add users.
I hope this helps!
Enjoy the weekend!