Keeper is an open-source calendar syncing tool that can be used to sync the blocks of time marked as "busy" on your personal, work, business and school calendars.
Canada
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OneCal AlternativesCalendar Apps like OneCal
OneCal is described as 'Productivity tool that aims to make calendar synchronization as easy as possible. It has a very intuitive UI, supports multi-way syncs, and is fully configurable (you can choose to sync event titles, descriptions, and participants, assign colors to clone events' and is a Calendar app in the office & productivity category. There are more than 10 alternatives to OneCal for Web-based, SaaS, iPhone and iPad. The best OneCal alternative is Keeper, which is both free and Open Source. Other great apps like OneCal are SyncThemCalendars, Kalender Sync, Neocal and SYNCDATE.
Alternatives list
14 Keeper alternatives
SyncThemCalendars allows you to block time in one calendar based on events in another calendar.
GDPR-compliant two-way calendar sync across Google, Outlook / Microsoft 365, iCloud, CalDAV and German providers like GMX. You choose per sync what is shared: busy only, title and time, or full details. Connects to Claude and ChatGPT via MCP. German company, German servers, DPA available.
Cost / License
- Freemium
- Proprietary
Platforms
- Online
- Software as a Service (SaaS)
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9 SYNCDATE alternativesCalendar sync utility that keeps Google Calendar events aligned across multiple accounts with privacy controls, sync health monitoring, and clean rollback.
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Calendar Family is a free, web-based calendar-sync service. It mirrors events in real time (webhook/push, not slow polling) across Google and Microsoft/Outlook, one-way or two-way, so you stop double-booking work and personal accounts.
Hetk syncs Google Calendar, Microsoft Outlook, and Apple iCloud in real time. Bi-directional sync, privacy controls that mask event details, and identity transformation.
Cost / License
- Paid
- Proprietary
Platforms
- Online
Multical is a calendar syncing app for fractionals, consultants, multi-hyphenates and portfolio careerists who want to stop getting double booked across clients.
Cost / License
- Paid
- Proprietary
Platforms
- Online
- Software as a Service (SaaS)
Programmable calendar sync that lets you filter and transform events as they move between Google Calendar, Outlook, and Apple Calendar.
Cost / License
- Freemium
- Proprietary
Application type
Platforms
- Online
- Software as a Service (SaaS)
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Sync Contacts, Calendar and Tasks automatically Across iPhone, Android, Outlook, Gmail and apps
Cost / License
- Paid
- Proprietary
Platforms
- iPhone
- iPad
- Software as a Service (SaaS)
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