Stop losing money
to last-minute
cancellations
FillOS connects to your Google Calendar and automatically fills cancelled appointments from a prioritized waitlist — so your schedule stays full, effortlessly.
Free until your first recovered slot · No credit card required
Monday, Feb 24
Today's Schedule
James Harrington
Initial consult
Aisha Mohammed
Follow-up session
Cancelled
Rachel Torres · same-day
Derek Saunders
Follow-up session
Why FillOS
Everything you need to fill every slot
Instant fill, zero effort
When a slot opens, FillOS ranks your waitlist and contacts the best match automatically.
Smart waitlist management
Guests self-serve onto your waitlist with their preferred times and flexibility.
Works with your calendar
Reads your Google Calendar to find real gaps. No double-booking, no extra setup.
The process
How it works
Set up once. FillOS runs in the background every time a cancellation hits.
Connect your calendar
Link your Google Calendar in one click. FillOS reads your schedule in real time.
Configure your waitlist
Set slot duration, buffer time, cancellation window, and fill mode.
Add people
Add clients manually, bulk-upload CSV, or share your waitlist link.
FillOS handles the rest
When a cancellation hits, FillOS fills the slot in minutes — automatically.
Simple, transparent pricing
Start free. Pay only after you see results.
Free tier
$0
Until your first recovered slot. No time limits.
- Google Calendar integration
- Unlimited waitlist entries
- Email notifications
- Basic analytics
Founding member
$39/mo
Lock in for life. Unlimited slots, full features.
- Everything in Free
- Priority slot filling
- SMS notifications
- Advanced analytics
- Early access to new features
Ready to stop leaving time on the table?
Founding pricing closes once we hit capacity.
Apply for early access →