HiCal vs One Calendar
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HiCal
This app facilitates collaborative event planning and scheduling for groups. Share timetables, receive real-time updates on changes, and communicate via comments. Ideal for students, project teams, and organizations to stay synchronized.
- Group event scheduling
- Real-time push notifications
- Event comments and discussion
- Shared timetables
- Private and public groups
- Event repetition support
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Organize yourselves for your classes, projects, or company with HiCal, the collaborative calendar! Create or join your class’ or club’s group, and get your shared timetable in your pocket. You can be part of multiple groups. You will receive Push notifications each time that a group’s event is modified, or an event is commented. Event repetition is supported (including “once every two weeks”). HiCal helps you to organize yourself and to collaborate with your friends and colleagues in different situations: - Students and pupils: Add comments to a lesson at a given day, to indicate homework and exams for example, and they will instantly be synced across smartphones and tablets, and shared with your class. You will not ever ask yourself again what is left to do: the answer will be in your pocket, up-to-date, at any moment. Even if only one person indicates the exams to come, everyone will be aware: one for all, and all for one! - Projects: Determine deadlines with your teammates, and discuss them in the comments! Your project is a secret? Then create a secret group, which will be hidden from the group search results. Only the people you add will be able to join the group. - Companies, clubs and organizations: Write down meetings’ or activities’ dates and locations, suggest or edit in real time, and instantly update all your fellows of a schedule change, thanks to push notifications. - Organize public events: Create a group, open to everyone, to let people stay tuned about your upcoming events! In this kind of group, only the group’s administrators can create or edit events. Thus, you can share your events, your live sessions for example if you’re a band, while keeping control. And if something unexpected happens, you can inform group’s members thanks to comments and push notifications! - Education: If you are an educational institution (school, college, university...), you can also use HiCal, by creating a group for each class or course, and inviting your students in them. Simplify your teachers’ and students’ life with HiCal!
One Calendar
Consolidate all your digital calendars into a single, easy-to-read view. Manage appointments, events, and birthdays from various providers like Google, Outlook, iCloud, and more, all within one application.
- Integrates multiple calendar providers
- Easy-to-read overview
- Manage appointments and events
- View birthdays
- Cross-platform availability
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The most popular app to view all your calendars like Google, Live, Outlook, iCloud, Exchange, Office365, Yahoo, Nextcloud, Synology, GMX, Mailbox.org, ownCloud and more. OneCalendar integrates all your calendars into an easy-to-read overview. View and manage all your appointments, events and birthdays. OneCalendar is available on all platforms.
Screenshots
Verdict
The clearest difference is in-app purchases: HiCal at none against One Calendar's 1. HiCal also leads on iOS requirement (13.0 vs 15.0). One Calendar's advantage is review sentiment (81% vs 55%) and ratings volume (21K vs 25). On price, rating, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. One Calendar sells 1 one-off in-app purchase. HiCal asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.8 for HiCal against 4.8 for One Calendar. That said, the two scores are not equally well evidenced: One Calendar has 21K ratings behind it against 25, so its average is the more settled of the two. Written reviews are what separate them: 55% of HiCal's written reviews are positive against 81% of One Calendar's.
HiCal ships an update every 2 months, One Calendar fortnightly. The most recent releases landed on October 21, 2026 and October 29, 2026 respectively.
| Parameter | HiCal | One Calendar |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (25 ratings) — better | 4.8 (21K ratings) |
| Positive reviews | 55.0% of reviews | 80.7% of reviews — better |
| Number of ratings | 25 | 21K — better |
| Update frequency | Every 2 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 13.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 3 MB | 89 MB |
| Age rating | 4+ | 12+ |
| Developer | Nakagawa Yugo | Code Spark |
Customer experience
HiCal
One Calendar
Bugs and requests
HiCal
Not enough reviews yet to summarise bugs or requests.
One Calendar
Reported bugs
5 issues- Sync errors
- Unresponsive buttons
- Incorrect time zone display
- Duplicate events
- Inability to delete future occurrences of recurring events
Requested features
6 requests- Multiple reminders for events
- Ability to edit recurring events
- Option to change event calendar after creation
- Printing support
- More customization options
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- Widgets for better visibility
In-app purchases
HiCal
No in-app purchases
One Calendar
- OneCalendar premium$5.99









