# One Calendar vs SID3KICK

The clearest difference is in-app purchases: SID3KICK at none against One Calendar's 1. SID3KICK also leads on update cadence (every 3 days vs fortnightly). One Calendar's advantage is device support (4 vs 2). On price, ads and iOS requirement there is nothing between them.

Both are free to download. One Calendar sells 1 one-off in-app purchase. SID3KICK asks for nothing beyond the download.

One Calendar ships an update fortnightly, SID3KICK every 3 days. The most recent releases landed on October 24, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | One Calendar | SID3KICK |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (21K ratings)](https://appshunter.io/ios/app/one-calendar/id1238379385/reviews)** | — |
| Number of ratings | **21K** | — |
| Positive reviews | 80.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 3 days** |
| Monetization | Free with in-app purchases | — |
| Size | 89 MB | 13 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Code Spark](https://appshunter.io/developer/1238379384) | [Codedatda.casa](https://appshunter.io/developer/6800890656) |

## What reviewers say

### One Calendar

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

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.

**Highlights:** Integrates multiple calendar providers, Easy-to-read overview, Manage appointments and events, View birthdays, Cross-platform availability

**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


### SID3KICK

[App page](https://appshunter.io/ios/app/sid3kick-your-second-brain/id6800933916)

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

**In-app purchases:** none


## Frequently asked questions

### Is One Calendar free?

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

### Is SID3KICK free?

SID3KICK is free to download, with no in-app purchases.

### Do One Calendar or SID3KICK have ads?

Neither One Calendar nor SID3KICK shows ads.

### Which is updated more often, One Calendar or SID3KICK?

One Calendar ships an update fortnightly, and SID3KICK every 3 days. Most recently, One Calendar was updated on October 24, 2026 and SID3KICK on October 11, 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.*