Hi everyone, I got such great advice last time, I'm back for more!

Our site has an appointment function, where customers schedule 1-on-1 appointments with our providers, and we are looking for a product (API) to allow customers to sign themselves up for timed appointment reminders (e.g., Would you like to send yourself an appointment reminder via text? If so, how many hours before your appointment?)

Additionally, we'd like to create an airBnB style messaging client between our providers and customers to where they can message one another, but through a third party SMS number (for privacy / security). 

We're considering Twilio for both, but I'm wondering if they offer the timed service, or would we build that portion ourselves? Any other products you all would recommend?

Thanks in advance!