Are there per-user fees or cancellation fees?
No. The plan you choose has a maximum number of members / devices / platforms for a fixed fee per month. For example, on the ‘Pro’ plan you can have up to 25 members/unlimited platforms & devices, and you will be charged one flat fee of USD$99 per month. You do not have to pay per individual user, and Ubertesters does not have any other fees or charges.