# O2 Calendar vs MobiFone eChatWork

The clearest difference is update cadence: O2 Calendar at every 4 days against MobiFone eChatWork's every 4 weeks. O2 Calendar also leads on iOS requirement (9.0 vs 13.4). On price, ads, in-app purchases and monetization model 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, MobiFone eChatWork every 4 weeks. The most recent releases landed on October 15, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | O2 Calendar | MobiFone eChatWork |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/mobifone-echatwork/id6443727434/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 4 weeks |
| Monetization | Free | Free |
| Size | 52 MB | 102 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) | [MobiFone](https://appshunter.io/developer/437730616) |

## 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


### MobiFone eChatWork

[App page](https://appshunter.io/ios/app/mobifone-echatwork/id6443727434)

This app facilitates communication and file sharing within teams. It allows users to easily message and discuss work-related tasks with group members, sharing files, images, and videos.

**Highlights:** Team messaging, File sharing (images, videos), Voice chat, Group work discussions, Information exchange

**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 MobiFone eChatWork free?

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

### Do O2 Calendar or MobiFone eChatWork have ads?

Neither O2 Calendar nor MobiFone eChatWork shows ads.

### Which is updated more often, O2 Calendar or MobiFone eChatWork?

O2 Calendar ships an update every 4 days, and MobiFone eChatWork every 4 weeks. Most recently, O2 Calendar was updated on October 15, 2026 and MobiFone eChatWork on October 13, 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.*