The ability for the cleaning service to be notified with a daily report of check-ins/check-outs. In fact this would probably just be a report and if reports could be scheduled to send automatically that would be perfect for this. Even better would be a kind of service through maybe twilio.com the cleaning service can text like "CLEAN 2" to say room 2 is now in the clean state.
I imagine a lot of these features could be sold as add-ons to the main package. I would gladly pay an extra $10 per month for this kind of "add-on" service.
We do currently support Third Party Alerts that send emails when a booking is created, updated or canceled. You may have seen those already.
A daily email would be good as well. I'm going to add this to the dev roadmap.
It's funny that you mention Twilio. We've discussed the idea of tracking *phone* inquiries by routing through Twilio or a similar service. Basically, you would point all your ads to a unique phone number which would give the inquirer a message about the property, ask if they want to check real time availability, leave a message or be connected to the owner. There are lots of possibilities in this area.
While the emails sent when the creation of the booking is good, I know our cleaning service isn't organized enough to manage bookings that are far out in the future, and in that case they are basically rebuilding the booking calendar. It's much easier for them to just have a list of check-ins/check-outs that they can pull up every day, or even better a daily email. Most of our cleaning team has smart phones but some just have phones that do simple messaging. The twilio idea is kind of like the way that hotel maids mark the room as clean through the phone system from the room itself but in this case its from a cell phone, more geared towards vacation rentals and simpler for the person cleaning.