OI Calendar

Private, encrypted calendar in the cloud

OI Calendar is a free and open source calendar app that stores event data in the user's own Blockstack storage (Gaia Hubs) rather than on the company's servers. It works across devices and pairs with an Android sync app.

12 alternatives to OI Calendar

Ranked by how well each tool replaces OI Calendar: shared features, audience, price and popularity.

Cozi
Family organizing app with a shared calendar, lists and reminders
Covers 0 of 6 key features.
Free plan
56 out of 100 matchContact sales
Vimcal
Calendar for people with too many meetings.
Covers 0 of 6 key features.
Free plan
53 out of 100 match$35/mo
DAViCal
A CalDAV Store.
Covers 0 of 6 key features.
Open source
52 out of 100 match—
nocal
Calendar, notes, and tasks with built-in MCP for AI agents
Covers 0 of 6 key features.
Free plan
51 out of 100 match$4.99/mo
Eventail
All your calendars right where you want them. Eventail is a power user's calendar home sc…
Covers 0 of 6 key features.
Free plan
49 out of 100 matchFree
Kin Calendar
The simple & connected calendar
Covers 0 of 6 key features.
48 out of 100 match—
Calendar
Team scheduling software and online calendar app
Covers 0 of 6 key features.
Free plan
47 out of 100 match$20/mo
Reclaim
AI Calendar for Work & Life
Covers 0 of 6 key features.
Free plan
46 out of 100 match$10/mo
Koalendar
Appointment scheduling software for booking meetings, intake forms and online payments
Covers 0 of 6 key features.
Free plan
46 out of 100 match$6.99/mo
ContactOffice
Secure collaboration platform
Covers 0 of 6 key features.
Free plan
45 out of 100 matchFree
OneCal
Sync your calendars, avoid scheduling conflicts
Covers 0 of 6 key features.
44 out of 100 match$5/mo
Keeper.sh
Stop double-booking yourself. Sync Google Calendar with Outlook & iCloud so all calendars,
Covers 0 of 6 key features.
Free planOpen source
44 out of 100 match$5/mo