# One Calendar vs FreeSlots Share Availability

The clearest difference is update cadence: FreeSlots Share Availability at weekly against One Calendar's every 3 weeks. One Calendar's advantage is device support (4 vs 1) and iOS requirement (15.0 vs 18.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. One Calendar sells 1 one-off in-app purchase and FreeSlots Share Availability sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

One Calendar ships an update every 3 weeks, FreeSlots Share Availability weekly. The most recent releases landed on November 11, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | One Calendar | FreeSlots Share Availability |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (21K ratings)](https://appshunter.io/ios/app/one-calendar/id1238379385/reviews)** | — |
| Number of ratings | **21K** | — |
| Positive reviews | 80.6% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Weekly** |
| Monetization | Free with in-app purchases | — |
| Size | 91 MB | 3 MB |
| Requires iOS | **15.0** | 18.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Code Spark](https://appshunter.io/developer/1238379384) | [Christopher Koch](https://appshunter.io/developer/6807182601) |

## What reviewers say

### One Calendar

[App page](https://appshunter.io/ios/app/one-calendar/id1238379385)

Consolidate all your calendars from various providers into a single, easy-to-read view. Manage appointments, events, and birthdays efficiently across all your devices. Offers a clean interface for seamless organization.

**Highlights:** Integrates multiple calendar providers, Unified calendar view, Manage appointments and events, Syncs across devices, Customizable colors and themes, Easy to use interface

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OneCalendar premium | $5.99 | one-time |

**What reviewers like**

- 🚀 Easy to use
- 👍 Clean and simple interface
- 👍 Integrates multiple calendars
- 🚀 Syncs across devices
- 👍 Customizable colors and themes

**What reviewers complain about**

- 🐛 Syncing issues
- 🐛 Bugs and glitches
- 🔒 Lacks security features
- 🔋 Drains battery
- 👎 Restrictive features in free version

**Reported bugs**

- Sync errors
- Unresponsive buttons
- Incorrect time zone display
- Duplicate events
- Inability to delete future occurrences of recurring events

**Requested features**

- Multiple reminders for events
- Ability to edit recurring events
- Option to change event calendar after creation
- Printing support
- More customization options


### FreeSlots Share Availability

[App page](https://appshunter.io/ios/app/freeslots-share-availability/id6808129276)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FreeSlots Pro | $3.99 | one-time |


## Frequently asked questions

### Is One Calendar free?

One Calendar is free to download, with in-app purchases available.

### Is FreeSlots Share Availability free?

FreeSlots Share Availability is free to download, with in-app purchases available.

### Do One Calendar or FreeSlots Share Availability have ads?

Neither One Calendar nor FreeSlots Share Availability shows ads.

### Which is updated more often, One Calendar or FreeSlots Share Availability?

One Calendar ships an update every 3 weeks, and FreeSlots Share Availability weekly. Most recently, One Calendar was updated on November 11, 2026 and FreeSlots Share Availability on November 6, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*