How some friends have suggested. The Ical need to be improved in three main skills.

1) Export Calendar

2) Import Multiply calendars

3) Auto import calendar.

I can explain you why it is the most important.

1) If I receive a booking from Traveler, I have to go to booking.com, airbnb.com, vrbo.es, and the rest of partners quickly before they make a new reservation. It is not useful

2) If I can add just one ical, per example booking.com. If I receive a booking from Airbnb, I have to introduce manually in traveler before somebody book the same periode in that rental. When you have one or two apartments, you can manage, but if you have 120 apartments it is a lots of work.

3) If I have to update manually ical, and I receive a booking when I am sleeping, until I wake up, I cannot update the calendar and I will receive other booking from Traveler and I will have an overbooking and I cannot cancel booking from partners, and people will prefer booking from them before me.

If we use your theme is because we need get more rentals with a professional website. If we have a beautiful web, but it is not useful for bookings, the main target of the web is not working.