To easy see when the next available time is, there are two different views, a list and a calendar to get a full overview of the week. The colours indicate if it's free, full or if it's possible to get on the waiting list if a time is canceled. A confirmation of the booking is required. Under bookings you can see an overview of your bookings and reservations.
The message function is there for you to report errors, inform other tenants and receive information from the landlord.
Under settings it's possible to customize your personal account after your needs.