Editorial disclosure: I work at Zellbox. TidyCal described from their Google Calendar integration docs as of August 2026.
TidyCal (an AppSumo/Sumo Group product) is a low-cost Calendly alternative. Zellbox adds WhatsApp reminders via the Google Calendar sync TidyCal already provides.
How it works
- In TidyCal → Integrations → Google Calendar → connect.
- In Zellbox → Onboarding step 2 → connect the same Google Calendar.
- Every TidyCal booking appears on your calendar. Zellbox fires WhatsApp reminders on schedule.
What Zellbox adds
- WhatsApp reminders — TidyCal sends email confirmations, not WhatsApp. Zellbox adds the message channel clients actually check for time-sensitive reminders, on top of TidyCal’s existing confirmation email.
- Signed consent PDFs for services requiring them. A consent PDF is captured on the client’s first reply and attached to their record automatically, no separate form needed.
- Two-way replies land in your Zellbox inbox. If a client replies to reschedule, that message lands somewhere your team can act on it instead of going nowhere.
Setup notes for lifetime-deal users
Licence type doesn’t change anything
Whether you bought TidyCal through its original AppSumo lifetime deal or a current subscription, bookings write to Google Calendar the same way — the Zellbox bridge works identically regardless of which TidyCal licence you’re on.
Free-tier-to-free-tier setup
TidyCal’s Google Calendar integration is available on its free plan, and Zellbox is free for essentials (100 reminders/month), so a low-cost or lifetime-deal TidyCal user can add WhatsApp reminders without any new recurring cost.
Feature summary
| Zellbox layer | TidyCal built-in | |
|---|---|---|
| Booking widget + payments | via TidyCal | Native |
| Email confirmations | Not the focus | Native |
| WhatsApp reminders | Native + free tier | Not available |
| Signed consent PDFs | Native | Not available |
~10 min end-to-end setup; free tier covers 100 reminders/mo.
About the author: Nacho Coll is the founder of Zellbox. He writes about WhatsApp Business automation for appointment-driven small businesses.
