If you choose the “Maximum participants” option for an event in the Spond app, the first members to accept the invitation will be able to attend. It's first come, first served, up to the limit you have set. Once this threshold has been reach, members will be placed on a reserve list, with spaces allocated in order of who responded first as they become available.
If someone attending withdraws from the event, the first person on the waiting list will receive a push notification regarding the free space, and will be able to accept or decline. If they decline, the next person on the waiting list will be offered the space, and so on.
The administrator cannot override the waiting list by moving someone up the list. However, they can add members to the waiting list, decline or remove them by going into the attendance list.
To disable the 'Maximum participants' feature and the waiting list, go to the event, select 'Edit' and press 'Remove" next to the max attendees number.
If there is a registration fee for the event, the member will not be asked to pay until they have accepted their place.