# O2 Calendar vs IDSpace

The clearest difference is update cadence: O2 Calendar at every 4 days against IDSpace's monthly. O2 Calendar also leads on iOS requirement (9.0 vs 13.4). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

O2 Calendar ships an update every 4 days, IDSpace monthly. The most recent releases landed on July 22, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | O2 Calendar | IDSpace |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 days** | Monthly |
| Monetization | Free | — |
| Size | 52 MB | 65 MB |
| Requires iOS | **9.0** | 13.4 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [O2 VN Tech.,JSC](https://appshunter.io/developer/1547745523) | [IDTEK JOINT STOCK COMPANY](https://appshunter.io/developer/1660194962) |

## What reviewers say

### O2 Calendar

[App page](https://appshunter.io/ios/app/o2-calendar/id1547745521)

Manage your schedule with this app, offering tools for events, appointments, notes, and daily tasks. Set custom reminders for your important activities and organize your day effectively.

**Highlights:** Event creation and management, Customizable event reminders, Daily task reminders, Note-taking functionality, Appointment scheduling

**Features:** macOS Compatibility

**In-app purchases:** none


### IDSpace

[App page](https://appshunter.io/ios/app/idspace/id6464384703)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is O2 Calendar free?

O2 Calendar is free to download, with no in-app purchases.

### Is IDSpace free?

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

### Do O2 Calendar or IDSpace have ads?

Neither O2 Calendar nor IDSpace shows ads.

### Which is updated more often, O2 Calendar or IDSpace?

O2 Calendar ships an update every 4 days, and IDSpace monthly. Most recently, O2 Calendar was updated on July 22, 2026 and IDSpace on September 19, 2026.

---

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